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llvm / llvm-project / 32ff98726b563bb6b0da99a9d0a61c6b37e5af73 / . / clang / lib / Sema / SemaLookup.cpp
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//===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements name lookup for C, C++, Objective-C, and
// Objective-C++.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclLookups.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/ModuleLoader.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Overload.h"
#include "clang/Sema/RISCVIntrinsicManager.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/Sema.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/SemaRISCV.h"
#include "clang/Sema/TemplateDeduction.h"
#include "clang/Sema/TypoCorrection.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/STLForwardCompat.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/ADT/edit_distance.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include <algorithm>
#include <iterator>
#include <list>
#include <optional>
#include <set>
#include <utility>
#include <vector>
#include "OpenCLBuiltins.inc"
using namespace clang;
using namespace sema;
namespace {
class UnqualUsingEntry {
const DeclContext *Nominated;
const DeclContext *CommonAncestor;
public:
UnqualUsingEntry(const DeclContext *Nominated,
const DeclContext *CommonAncestor)
: Nominated(Nominated), CommonAncestor(CommonAncestor) {
}
const DeclContext *getCommonAncestor() const {
return CommonAncestor;
}
const DeclContext *getNominatedNamespace() const {
return Nominated;
}
// Sort by the pointer value of the common ancestor.
struct Comparator {
bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
return L.getCommonAncestor() < R.getCommonAncestor();
}
bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
return E.getCommonAncestor() < DC;
}
bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
return DC < E.getCommonAncestor();
}
};
};
/// A collection of using directives, as used by C++ unqualified
/// lookup.
class UnqualUsingDirectiveSet {
Sema &SemaRef;
typedef SmallVector<UnqualUsingEntry, 8> ListTy;
ListTy list;
llvm::SmallPtrSet<DeclContext*, 8> visited;
public:
UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {}
void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
// C++ [namespace.udir]p1:
// During unqualified name lookup, the names appear as if they
// were declared in the nearest enclosing namespace which contains
// both the using-directive and the nominated namespace.
DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
assert(InnermostFileDC && InnermostFileDC->isFileContext());
for (; S; S = S->getParent()) {
// C++ [namespace.udir]p1:
// A using-directive shall not appear in class scope, but may
// appear in namespace scope or in block scope.
DeclContext *Ctx = S->getEntity();
if (Ctx && Ctx->isFileContext()) {
visit(Ctx, Ctx);
} else if (!Ctx || Ctx->isFunctionOrMethod()) {
for (auto *I : S->using_directives())
if (SemaRef.isVisible(I))
visit(I, InnermostFileDC);
}
}
}
// Visits a context and collect all of its using directives
// recursively. Treats all using directives as if they were
// declared in the context.
//
// A given context is only every visited once, so it is important
// that contexts be visited from the inside out in order to get
// the effective DCs right.
void visit(DeclContext *DC, DeclContext *EffectiveDC) {
if (!visited.insert(DC).second)
return;
addUsingDirectives(DC, EffectiveDC);
}
// Visits a using directive and collects all of its using
// directives recursively. Treats all using directives as if they
// were declared in the effective DC.
void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
DeclContext *NS = UD->getNominatedNamespace();
if (!visited.insert(NS).second)
return;
addUsingDirective(UD, EffectiveDC);
addUsingDirectives(NS, EffectiveDC);
}
// Adds all the using directives in a context (and those nominated
// by its using directives, transitively) as if they appeared in
// the given effective context.
void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
SmallVector<DeclContext*, 4> queue;
while (true) {
for (auto *UD : DC->using_directives()) {
DeclContext *NS = UD->getNominatedNamespace();
if (SemaRef.isVisible(UD) && visited.insert(NS).second) {
addUsingDirective(UD, EffectiveDC);
queue.push_back(NS);
}
}
if (queue.empty())
return;
DC = queue.pop_back_val();
}
}
// Add a using directive as if it had been declared in the given
// context. This helps implement C++ [namespace.udir]p3:
// The using-directive is transitive: if a scope contains a
// using-directive that nominates a second namespace that itself
// contains using-directives, the effect is as if the
// using-directives from the second namespace also appeared in
// the first.
void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
// Find the common ancestor between the effective context and
// the nominated namespace.
DeclContext *Common = UD->getNominatedNamespace();
while (!Common->Encloses(EffectiveDC))
Common = Common->getParent();
Common = Common->getPrimaryContext();
list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
}
void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); }
typedef ListTy::const_iterator const_iterator;
const_iterator begin() const { return list.begin(); }
const_iterator end() const { return list.end(); }
llvm::iterator_range<const_iterator>
getNamespacesFor(const DeclContext *DC) const {
return llvm::make_range(std::equal_range(begin(), end(),
DC->getPrimaryContext(),
UnqualUsingEntry::Comparator()));
}
};
} // end anonymous namespace
// Retrieve the set of identifier namespaces that correspond to a
// specific kind of name lookup.
static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
bool CPlusPlus,
bool Redeclaration) {
unsigned IDNS = 0;
switch (NameKind) {
case Sema::LookupObjCImplicitSelfParam:
case Sema::LookupOrdinaryName:
case Sema::LookupRedeclarationWithLinkage:
case Sema::LookupLocalFriendName:
case Sema::LookupDestructorName:
IDNS = Decl::IDNS_Ordinary;
if (CPlusPlus) {
IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
if (Redeclaration)
IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
}
if (Redeclaration)
IDNS |= Decl::IDNS_LocalExtern;
break;
case Sema::LookupOperatorName:
// Operator lookup is its own crazy thing; it is not the same
// as (e.g.) looking up an operator name for redeclaration.
assert(!Redeclaration && "cannot do redeclaration operator lookup");
IDNS = Decl::IDNS_NonMemberOperator;
break;
case Sema::LookupTagName:
if (CPlusPlus) {
IDNS = Decl::IDNS_Type;
// When looking for a redeclaration of a tag name, we add:
// 1) TagFriend to find undeclared friend decls
// 2) Namespace because they can't "overload" with tag decls.
// 3) Tag because it includes class templates, which can't
// "overload" with tag decls.
if (Redeclaration)
IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
} else {
IDNS = Decl::IDNS_Tag;
}
break;
case Sema::LookupLabel:
IDNS = Decl::IDNS_Label;
break;
case Sema::LookupMemberName:
IDNS = Decl::IDNS_Member;
if (CPlusPlus)
IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
break;
case Sema::LookupNestedNameSpecifierName:
IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
break;
case Sema::LookupNamespaceName:
IDNS = Decl::IDNS_Namespace;
break;
case Sema::LookupUsingDeclName:
assert(Redeclaration && "should only be used for redecl lookup");
IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
Decl::IDNS_LocalExtern;
break;
case Sema::LookupObjCProtocolName:
IDNS = Decl::IDNS_ObjCProtocol;
break;
case Sema::LookupOMPReductionName:
IDNS = Decl::IDNS_OMPReduction;
break;
case Sema::LookupOMPMapperName:
IDNS = Decl::IDNS_OMPMapper;
break;
case Sema::LookupAnyName:
IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
| Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
| Decl::IDNS_Type;
break;
}
return IDNS;
}
void LookupResult::configure() {
IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
isForRedeclaration());
// If we're looking for one of the allocation or deallocation
// operators, make sure that the implicitly-declared new and delete
// operators can be found.
switch (NameInfo.getName().getCXXOverloadedOperator()) {
case OO_New:
case OO_Delete:
case OO_Array_New:
case OO_Array_Delete:
getSema().DeclareGlobalNewDelete();
break;
default:
break;
}
// Compiler builtins are always visible, regardless of where they end
// up being declared.
if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
if (unsigned BuiltinID = Id->getBuiltinID()) {
if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
AllowHidden = true;
}
}
}
bool LookupResult::checkDebugAssumptions() const {
// This function is never called by NDEBUG builds.
assert(ResultKind != LookupResultKind::NotFound || Decls.size() == 0);
assert(ResultKind != LookupResultKind::Found || Decls.size() == 1);
assert(ResultKind != LookupResultKind::FoundOverloaded || Decls.size() > 1 ||
(Decls.size() == 1 &&
isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
assert(ResultKind != LookupResultKind::FoundUnresolvedValue ||
checkUnresolved());
assert(ResultKind != LookupResultKind::Ambiguous || Decls.size() > 1 ||
(Decls.size() == 1 &&
(Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjects ||
Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjectTypes)));
assert((Paths != nullptr) ==
(ResultKind == LookupResultKind::Ambiguous &&
(Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjectTypes ||
Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjects)));
return true;
}
// Necessary because CXXBasePaths is not complete in Sema.h
void LookupResult::deletePaths(CXXBasePaths *Paths) {
delete Paths;
}
/// Get a representative context for a declaration such that two declarations
/// will have the same context if they were found within the same scope.
static const DeclContext *getContextForScopeMatching(const Decl *D) {
// For function-local declarations, use that function as the context. This
// doesn't account for scopes within the function; the caller must deal with
// those.
if (const DeclContext *DC = D->getLexicalDeclContext();
DC->isFunctionOrMethod())
return DC;
// Otherwise, look at the semantic context of the declaration. The
// declaration must have been found there.
return D->getDeclContext()->getRedeclContext();
}
/// Determine whether \p D is a better lookup result than \p Existing,
/// given that they declare the same entity.
static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
const NamedDecl *D,
const NamedDecl *Existing) {
// When looking up redeclarations of a using declaration, prefer a using
// shadow declaration over any other declaration of the same entity.
if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
!isa<UsingShadowDecl>(Existing))
return true;
const auto *DUnderlying = D->getUnderlyingDecl();
const auto *EUnderlying = Existing->getUnderlyingDecl();
// If they have different underlying declarations, prefer a typedef over the
// original type (this happens when two type declarations denote the same
// type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
// might carry additional semantic information, such as an alignment override.
// However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
// declaration over a typedef. Also prefer a tag over a typedef for
// destructor name lookup because in some contexts we only accept a
// class-name in a destructor declaration.
if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
bool HaveTag = isa<TagDecl>(EUnderlying);
bool WantTag =
Kind == Sema::LookupTagName || Kind == Sema::LookupDestructorName;
return HaveTag != WantTag;
}
// Pick the function with more default arguments.
// FIXME: In the presence of ambiguous default arguments, we should keep both,
// so we can diagnose the ambiguity if the default argument is needed.
// See C++ [over.match.best]p3.
if (const auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
const auto *EFD = cast<FunctionDecl>(EUnderlying);
unsigned DMin = DFD->getMinRequiredArguments();
unsigned EMin = EFD->getMinRequiredArguments();
// If D has more default arguments, it is preferred.
if (DMin != EMin)
return DMin < EMin;
// FIXME: When we track visibility for default function arguments, check
// that we pick the declaration with more visible default arguments.
}
// Pick the template with more default template arguments.
if (const auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
const auto *ETD = cast<TemplateDecl>(EUnderlying);
unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
// If D has more default arguments, it is preferred. Note that default
// arguments (and their visibility) is monotonically increasing across the
// redeclaration chain, so this is a quick proxy for "is more recent".
if (DMin != EMin)
return DMin < EMin;
// If D has more *visible* default arguments, it is preferred. Note, an
// earlier default argument being visible does not imply that a later
// default argument is visible, so we can't just check the first one.
for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
I != N; ++I) {
if (!S.hasVisibleDefaultArgument(
ETD->getTemplateParameters()->getParam(I)) &&
S.hasVisibleDefaultArgument(
DTD->getTemplateParameters()->getParam(I)))
return true;
}
}
// VarDecl can have incomplete array types, prefer the one with more complete
// array type.
if (const auto *DVD = dyn_cast<VarDecl>(DUnderlying)) {
const auto *EVD = cast<VarDecl>(EUnderlying);
if (EVD->getType()->isIncompleteType() &&
!DVD->getType()->isIncompleteType()) {
// Prefer the decl with a more complete type if visible.
return S.isVisible(DVD);
}
return false; // Avoid picking up a newer decl, just because it was newer.
}
// For most kinds of declaration, it doesn't really matter which one we pick.
if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
// If the existing declaration is hidden, prefer the new one. Otherwise,
// keep what we've got.
return !S.isVisible(Existing);
}
// Pick the newer declaration; it might have a more precise type.
for (const Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
Prev = Prev->getPreviousDecl())
if (Prev == EUnderlying)
return true;
return false;
}
/// Determine whether \p D can hide a tag declaration.
static bool canHideTag(const NamedDecl *D) {
// C++ [basic.scope.declarative]p4:
// Given a set of declarations in a single declarative region [...]
// exactly one declaration shall declare a class name or enumeration name
// that is not a typedef name and the other declarations shall all refer to
// the same variable, non-static data member, or enumerator, or all refer
// to functions and function templates; in this case the class name or
// enumeration name is hidden.
// C++ [basic.scope.hiding]p2:
// A class name or enumeration name can be hidden by the name of a
// variable, data member, function, or enumerator declared in the same
// scope.
// An UnresolvedUsingValueDecl always instantiates to one of these.
D = D->getUnderlyingDecl();
return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
isa<UnresolvedUsingValueDecl>(D);
}
/// Resolves the result kind of this lookup.
void LookupResult::resolveKind() {
unsigned N = Decls.size();
// Fast case: no possible ambiguity.
if (N == 0) {
assert(ResultKind == LookupResultKind::NotFound ||
ResultKind == LookupResultKind::NotFoundInCurrentInstantiation);
return;
}
// If there's a single decl, we need to examine it to decide what
// kind of lookup this is.
if (N == 1) {
const NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
if (isa<FunctionTemplateDecl>(D))
ResultKind = LookupResultKind::FoundOverloaded;
else if (isa<UnresolvedUsingValueDecl>(D))
ResultKind = LookupResultKind::FoundUnresolvedValue;
return;
}
// Don't do any extra resolution if we've already resolved as ambiguous.
if (ResultKind == LookupResultKind::Ambiguous)
return;
llvm::SmallDenseMap<const NamedDecl *, unsigned, 16> Unique;
llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
bool Ambiguous = false;
bool ReferenceToPlaceHolderVariable = false;
bool HasTag = false, HasFunction = false;
bool HasFunctionTemplate = false, HasUnresolved = false;
const NamedDecl *HasNonFunction = nullptr;
llvm::SmallVector<const NamedDecl *, 4> EquivalentNonFunctions;
llvm::BitVector RemovedDecls(N);
for (unsigned I = 0; I < N; I++) {
const NamedDecl *D = Decls[I]->getUnderlyingDecl();
D = cast<NamedDecl>(D->getCanonicalDecl());
// Ignore an invalid declaration unless it's the only one left.
// Also ignore HLSLBufferDecl which not have name conflict with other Decls.
if ((D->isInvalidDecl() || isa<HLSLBufferDecl>(D)) &&
N - RemovedDecls.count() > 1) {
RemovedDecls.set(I);
continue;
}
// C++ [basic.scope.hiding]p2:
// A class name or enumeration name can be hidden by the name of
// an object, function, or enumerator declared in the same
// scope. If a class or enumeration name and an object, function,
// or enumerator are declared in the same scope (in any order)
// with the same name, the class or enumeration name is hidden
// wherever the object, function, or enumerator name is visible.
if (HideTags && isa<TagDecl>(D)) {
bool Hidden = false;
for (auto *OtherDecl : Decls) {
if (canHideTag(OtherDecl) && !OtherDecl->isInvalidDecl() &&
getContextForScopeMatching(OtherDecl)->Equals(
getContextForScopeMatching(Decls[I]))) {
RemovedDecls.set(I);
Hidden = true;
break;
}
}
if (Hidden)
continue;
}
std::optional<unsigned> ExistingI;
// Redeclarations of types via typedef can occur both within a scope
// and, through using declarations and directives, across scopes. There is
// no ambiguity if they all refer to the same type, so unique based on the
// canonical type.
if (const auto *TD = dyn_cast<TypeDecl>(D)) {
auto UniqueResult = UniqueTypes.insert(
std::make_pair(getSema().Context.getCanonicalTypeDeclType(TD), I));
if (!UniqueResult.second) {
// The type is not unique.
ExistingI = UniqueResult.first->second;
}
}
// For non-type declarations, check for a prior lookup result naming this
// canonical declaration.
if (!ExistingI) {
auto UniqueResult = Unique.insert(std::make_pair(D, I));
if (!UniqueResult.second) {
// We've seen this entity before.
ExistingI = UniqueResult.first->second;
}
}
if (ExistingI) {
// This is not a unique lookup result. Pick one of the results and
// discard the other.
if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
Decls[*ExistingI]))
Decls[*ExistingI] = Decls[I];
RemovedDecls.set(I);
continue;
}
// Otherwise, do some decl type analysis and then continue.
if (isa<UnresolvedUsingValueDecl>(D)) {
HasUnresolved = true;
} else if (isa<TagDecl>(D)) {
if (HasTag)
Ambiguous = true;
HasTag = true;
} else if (isa<FunctionTemplateDecl>(D)) {
HasFunction = true;
HasFunctionTemplate = true;
} else if (isa<FunctionDecl>(D)) {
HasFunction = true;
} else {
if (HasNonFunction) {
// If we're about to create an ambiguity between two declarations that
// are equivalent, but one is an internal linkage declaration from one
// module and the other is an internal linkage declaration from another
// module, just skip it.
if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
D)) {
EquivalentNonFunctions.push_back(D);
RemovedDecls.set(I);
continue;
}
if (D->isPlaceholderVar(getSema().getLangOpts()) &&
getContextForScopeMatching(D) ==
getContextForScopeMatching(Decls[I])) {
ReferenceToPlaceHolderVariable = true;
}
Ambiguous = true;
}
HasNonFunction = D;
}
}
// FIXME: This diagnostic should really be delayed until we're done with
// the lookup result, in case the ambiguity is resolved by the caller.
if (!EquivalentNonFunctions.empty() && !Ambiguous)
getSema().diagnoseEquivalentInternalLinkageDeclarations(
getNameLoc(), HasNonFunction, EquivalentNonFunctions);
// Remove decls by replacing them with decls from the end (which
// means that we need to iterate from the end) and then truncating
// to the new size.
for (int I = RemovedDecls.find_last(); I >= 0; I = RemovedDecls.find_prev(I))
Decls[I] = Decls[--N];
Decls.truncate(N);
if ((HasNonFunction && (HasFunction || HasUnresolved)) ||
(HideTags && HasTag && (HasFunction || HasNonFunction || HasUnresolved)))
Ambiguous = true;
if (Ambiguous && ReferenceToPlaceHolderVariable)
setAmbiguous(LookupAmbiguityKind::AmbiguousReferenceToPlaceholderVariable);
else if (Ambiguous)
setAmbiguous(LookupAmbiguityKind::AmbiguousReference);
else if (HasUnresolved)
ResultKind = LookupResultKind::FoundUnresolvedValue;
else if (N > 1 || HasFunctionTemplate)
ResultKind = LookupResultKind::FoundOverloaded;
else
ResultKind = LookupResultKind::Found;
}
void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
CXXBasePaths::const_paths_iterator I, E;
for (I = P.begin(), E = P.end(); I != E; ++I)
for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE;
++DI)
addDecl(*DI);
}
void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
Paths = new CXXBasePaths;
Paths->swap(P);
addDeclsFromBasePaths(*Paths);
resolveKind();
setAmbiguous(LookupAmbiguityKind::AmbiguousBaseSubobjects);
}
void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
Paths = new CXXBasePaths;
Paths->swap(P);
addDeclsFromBasePaths(*Paths);
resolveKind();
setAmbiguous(LookupAmbiguityKind::AmbiguousBaseSubobjectTypes);
}
void LookupResult::print(raw_ostream &Out) {
Out << Decls.size() << " result(s)";
if (isAmbiguous()) Out << ", ambiguous";
if (Paths) Out << ", base paths present";
for (iterator I = begin(), E = end(); I != E; ++I) {
Out << "\n";
(*I)->print(Out, 2);
}
}
LLVM_DUMP_METHOD void LookupResult::dump() {
llvm::errs() << "lookup results for " << getLookupName().getAsString()
<< ":\n";
for (NamedDecl *D : *this)
D->dump();
}
/// Diagnose a missing builtin type.
static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass,
llvm::StringRef Name) {
S.Diag(SourceLocation(), diag::err_opencl_type_not_found)
<< TypeClass << Name;
return S.Context.VoidTy;
}
/// Lookup an OpenCL enum type.
static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) {
LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
Sema::LookupTagName);
S.LookupName(Result, S.TUScope);
if (Result.empty())
return diagOpenCLBuiltinTypeError(S, "enum", Name);
EnumDecl *Decl = Result.getAsSingle<EnumDecl>();
if (!Decl)
return diagOpenCLBuiltinTypeError(S, "enum", Name);
return S.Context.getCanonicalTagType(Decl);
}
/// Lookup an OpenCL typedef type.
static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) {
LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
Sema::LookupOrdinaryName);
S.LookupName(Result, S.TUScope);
if (Result.empty())
return diagOpenCLBuiltinTypeError(S, "typedef", Name);
TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>();
if (!Decl)
return diagOpenCLBuiltinTypeError(S, "typedef", Name);
return S.Context.getTypedefType(ElaboratedTypeKeyword::None,
/*Qualifier=*/std::nullopt, Decl);
}
/// Get the QualType instances of the return type and arguments for an OpenCL
/// builtin function signature.
/// \param S (in) The Sema instance.
/// \param OpenCLBuiltin (in) The signature currently handled.
/// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
/// type used as return type or as argument.
/// Only meaningful for generic types, otherwise equals 1.
/// \param RetTypes (out) List of the possible return types.
/// \param ArgTypes (out) List of the possible argument types. For each
/// argument, ArgTypes contains QualTypes for the Cartesian product
/// of (vector sizes) x (types) .
static void GetQualTypesForOpenCLBuiltin(
Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt,
SmallVector<QualType, 1> &RetTypes,
SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
// Get the QualType instances of the return types.
unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
OCL2Qual(S, TypeTable[Sig], RetTypes);
GenTypeMaxCnt = RetTypes.size();
// Get the QualType instances of the arguments.
// First type is the return type, skip it.
for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
SmallVector<QualType, 1> Ty;
OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]],
Ty);
GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
ArgTypes.push_back(std::move(Ty));
}
}
/// Create a list of the candidate function overloads for an OpenCL builtin
/// function.
/// \param Context (in) The ASTContext instance.
/// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
/// type used as return type or as argument.
/// Only meaningful for generic types, otherwise equals 1.
/// \param FunctionList (out) List of FunctionTypes.
/// \param RetTypes (in) List of the possible return types.
/// \param ArgTypes (in) List of the possible types for the arguments.
static void GetOpenCLBuiltinFctOverloads(
ASTContext &Context, unsigned GenTypeMaxCnt,
std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes,
SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
FunctionProtoType::ExtProtoInfo PI(
Context.getTargetInfo().getDefaultCallingConv());
PI.Variadic = false;
// Do not attempt to create any FunctionTypes if there are no return types,
// which happens when a type belongs to a disabled extension.
if (RetTypes.size() == 0)
return;
// Create FunctionTypes for each (gen)type.
for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
SmallVector<QualType, 5> ArgList;
for (unsigned A = 0; A < ArgTypes.size(); A++) {
// Bail out if there is an argument that has no available types.
if (ArgTypes[A].size() == 0)
return;
// Builtins such as "max" have an "sgentype" argument that represents
// the corresponding scalar type of a gentype. The number of gentypes
// must be a multiple of the number of sgentypes.
assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
"argument type count not compatible with gentype type count");
unsigned Idx = IGenType % ArgTypes[A].size();
ArgList.push_back(ArgTypes[A][Idx]);
}
FunctionList.push_back(Context.getFunctionType(
RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI));
}
}
/// When trying to resolve a function name, if isOpenCLBuiltin() returns a
/// non-null <Index, Len> pair, then the name is referencing an OpenCL
/// builtin function. Add all candidate signatures to the LookUpResult.
///
/// \param S (in) The Sema instance.
/// \param LR (inout) The LookupResult instance.
/// \param II (in) The identifier being resolved.
/// \param FctIndex (in) Starting index in the BuiltinTable.
/// \param Len (in) The signature list has Len elements.
static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR,
IdentifierInfo *II,
const unsigned FctIndex,
const unsigned Len) {
// The builtin function declaration uses generic types (gentype).
bool HasGenType = false;
// Maximum number of types contained in a generic type used as return type or
// as argument. Only meaningful for generic types, otherwise equals 1.
unsigned GenTypeMaxCnt;
ASTContext &Context = S.Context;
for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
const OpenCLBuiltinStruct &OpenCLBuiltin =
BuiltinTable[FctIndex + SignatureIndex];
// Ignore this builtin function if it is not available in the currently
// selected language version.
if (!isOpenCLVersionContainedInMask(Context.getLangOpts(),
OpenCLBuiltin.Versions))
continue;
// Ignore this builtin function if it carries an extension macro that is
// not defined. This indicates that the extension is not supported by the
// target, so the builtin function should not be available.
StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension];
if (!Extensions.empty()) {
SmallVector<StringRef, 2> ExtVec;
Extensions.split(ExtVec, " ");
bool AllExtensionsDefined = true;
for (StringRef Ext : ExtVec) {
if (!S.getPreprocessor().isMacroDefined(Ext)) {
AllExtensionsDefined = false;
break;
}
}
if (!AllExtensionsDefined)
continue;
}
SmallVector<QualType, 1> RetTypes;
SmallVector<SmallVector<QualType, 1>, 5> ArgTypes;
// Obtain QualType lists for the function signature.
GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes,
ArgTypes);
if (GenTypeMaxCnt > 1) {
HasGenType = true;
}
// Create function overload for each type combination.
std::vector<QualType> FunctionList;
GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
ArgTypes);
SourceLocation Loc = LR.getNameLoc();
DeclContext *Parent = Context.getTranslationUnitDecl();
FunctionDecl *NewOpenCLBuiltin;
for (const auto &FTy : FunctionList) {
NewOpenCLBuiltin = FunctionDecl::Create(
Context, Parent, Loc, Loc, II, FTy, /*TInfo=*/nullptr, SC_Extern,
S.getCurFPFeatures().isFPConstrained(), false,
FTy->isFunctionProtoType());
NewOpenCLBuiltin->setImplicit();
// Create Decl objects for each parameter, adding them to the
// FunctionDecl.
const auto *FP = cast<FunctionProtoType>(FTy);
SmallVector<ParmVarDecl *, 4> ParmList;
for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
ParmVarDecl *Parm = ParmVarDecl::Create(
Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(),
nullptr, FP->getParamType(IParm), nullptr, SC_None, nullptr);
Parm->setScopeInfo(0, IParm);
ParmList.push_back(Parm);
}
NewOpenCLBuiltin->setParams(ParmList);
// Add function attributes.
if (OpenCLBuiltin.IsPure)
NewOpenCLBuiltin->addAttr(PureAttr::CreateImplicit(Context));
if (OpenCLBuiltin.IsConst)
NewOpenCLBuiltin->addAttr(ConstAttr::CreateImplicit(Context));
if (OpenCLBuiltin.IsConv)
NewOpenCLBuiltin->addAttr(ConvergentAttr::CreateImplicit(Context));
if (!S.getLangOpts().OpenCLCPlusPlus)
NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context));
LR.addDecl(NewOpenCLBuiltin);
}
}
// If we added overloads, need to resolve the lookup result.
if (Len > 1 || HasGenType)
LR.resolveKind();
}
bool Sema::LookupBuiltin(LookupResult &R) {
Sema::LookupNameKind NameKind = R.getLookupKind();
// If we didn't find a use of this identifier, and if the identifier
// corresponds to a compiler builtin, create the decl object for the builtin
// now, injecting it into translation unit scope, and return it.
if (NameKind == Sema::LookupOrdinaryName ||
NameKind == Sema::LookupRedeclarationWithLinkage) {
IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
if (II) {
if (NameKind == Sema::LookupOrdinaryName) {
if (getLangOpts().CPlusPlus) {
#define BuiltinTemplate(BIName)
#define CPlusPlusBuiltinTemplate(BIName) \
if (II == getASTContext().get##BIName##Name()) { \
R.addDecl(getASTContext().get##BIName##Decl()); \
return true; \
}
#include "clang/Basic/BuiltinTemplates.inc"
}
if (getLangOpts().HLSL) {
#define BuiltinTemplate(BIName)
#define HLSLBuiltinTemplate(BIName) \
if (II == getASTContext().get##BIName##Name()) { \
R.addDecl(getASTContext().get##BIName##Decl()); \
return true; \
}
#include "clang/Basic/BuiltinTemplates.inc"
}
}
// Check if this is an OpenCL Builtin, and if so, insert its overloads.
if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) {
auto Index = isOpenCLBuiltin(II->getName());
if (Index.first) {
InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1,
Index.second);
return true;
}
}
if (RISCV().DeclareRVVBuiltins || RISCV().DeclareSiFiveVectorBuiltins ||
RISCV().DeclareAndesVectorBuiltins) {
if (!RISCV().IntrinsicManager)
RISCV().IntrinsicManager = CreateRISCVIntrinsicManager(*this);
RISCV().IntrinsicManager->InitIntrinsicList();
if (RISCV().IntrinsicManager->CreateIntrinsicIfFound(R, II, PP))
return true;
}
// If this is a builtin on this (or all) targets, create the decl.
if (unsigned BuiltinID = II->getBuiltinID()) {
// In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
// library functions like 'malloc'. Instead, we'll just error.
if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) &&
Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
return false;
if (NamedDecl *D =
LazilyCreateBuiltin(II, BuiltinID, TUScope,
R.isForRedeclaration(), R.getNameLoc())) {
R.addDecl(D);
return true;
}
}
}
}
return false;
}
/// Looks up the declaration of "struct objc_super" and
/// saves it for later use in building builtin declaration of
/// objc_msgSendSuper and objc_msgSendSuper_stret.
static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S) {
ASTContext &Context = Sema.Context;
LookupResult Result(Sema, &Context.Idents.get("objc_super"), SourceLocation(),
Sema::LookupTagName);
Sema.LookupName(Result, S);
if (Result.getResultKind() == LookupResultKind::Found)
if (const TagDecl *TD = Result.getAsSingle<TagDecl>())
Context.setObjCSuperType(Context.getCanonicalTagType(TD));
}
void Sema::LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID) {
if (ID == Builtin::BIobjc_msgSendSuper)
LookupPredefedObjCSuperType(*this, S);
}
/// Determine whether we can declare a special member function within
/// the class at this point.
static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
// We need to have a definition for the class.
if (!Class->getDefinition() || Class->isDependentContext())
return false;
// We can't be in the middle of defining the class.
return !Class->isBeingDefined();
}
void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
if (!CanDeclareSpecialMemberFunction(Class))
return;
// If the default constructor has not yet been declared, do so now.
if (Class->needsImplicitDefaultConstructor())
DeclareImplicitDefaultConstructor(Class);
// If the copy constructor has not yet been declared, do so now.
if (Class->needsImplicitCopyConstructor())
DeclareImplicitCopyConstructor(Class);
// If the copy assignment operator has not yet been declared, do so now.
if (Class->needsImplicitCopyAssignment())
DeclareImplicitCopyAssignment(Class);
if (getLangOpts().CPlusPlus11) {
// If the move constructor has not yet been declared, do so now.
if (Class->needsImplicitMoveConstructor())
DeclareImplicitMoveConstructor(Class);
// If the move assignment operator has not yet been declared, do so now.
if (Class->needsImplicitMoveAssignment())
DeclareImplicitMoveAssignment(Class);
}
// If the destructor has not yet been declared, do so now.
if (Class->needsImplicitDestructor())
DeclareImplicitDestructor(Class);
}
/// Determine whether this is the name of an implicitly-declared
/// special member function.
static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
switch (Name.getNameKind()) {
case DeclarationName::CXXConstructorName:
case DeclarationName::CXXDestructorName:
return true;
case DeclarationName::CXXOperatorName:
return Name.getCXXOverloadedOperator() == OO_Equal;
default:
break;
}
return false;
}
/// If there are any implicit member functions with the given name
/// that need to be declared in the given declaration context, do so.
static void DeclareImplicitMemberFunctionsWithName(Sema &S,
DeclarationName Name,
SourceLocation Loc,
const DeclContext *DC) {
if (!DC)
return;
switch (Name.getNameKind()) {
case DeclarationName::CXXConstructorName:
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
if (Record->needsImplicitDefaultConstructor())
S.DeclareImplicitDefaultConstructor(Class);
if (Record->needsImplicitCopyConstructor())
S.DeclareImplicitCopyConstructor(Class);
if (S.getLangOpts().CPlusPlus11 &&
Record->needsImplicitMoveConstructor())
S.DeclareImplicitMoveConstructor(Class);
}
break;
case DeclarationName::CXXDestructorName:
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
if (Record->getDefinition() && Record->needsImplicitDestructor() &&
CanDeclareSpecialMemberFunction(Record))
S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
break;
case DeclarationName::CXXOperatorName:
if (Name.getCXXOverloadedOperator() != OO_Equal)
break;
if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
if (Record->needsImplicitCopyAssignment())
S.DeclareImplicitCopyAssignment(Class);
if (S.getLangOpts().CPlusPlus11 &&
Record->needsImplicitMoveAssignment())
S.DeclareImplicitMoveAssignment(Class);
}
}
break;
case DeclarationName::CXXDeductionGuideName:
S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc);
break;
default:
break;
}
}
// Adds all qualifying matches for a name within a decl context to the
// given lookup result. Returns true if any matches were found.
static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
bool Found = false;
// Lazily declare C++ special member functions.
if (S.getLangOpts().CPlusPlus)
DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(),
DC);
// Perform lookup into this declaration context.
DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
for (NamedDecl *D : DR) {
if ((D = R.getAcceptableDecl(D))) {
R.addDecl(D);
Found = true;
}
}
if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R))
return true;
if (R.getLookupName().getNameKind()
!= DeclarationName::CXXConversionFunctionName ||
R.getLookupName().getCXXNameType()->isDependentType() ||
!isa<CXXRecordDecl>(DC))
return Found;
// C++ [temp.mem]p6:
// A specialization of a conversion function template is not found by
// name lookup. Instead, any conversion function templates visible in the
// context of the use are considered. [...]
const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
if (!Record->isCompleteDefinition())
return Found;
// For conversion operators, 'operator auto' should only match
// 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
// as a candidate for template substitution.
auto *ContainedDeducedType =
R.getLookupName().getCXXNameType()->getContainedDeducedType();
if (R.getLookupName().getNameKind() ==
DeclarationName::CXXConversionFunctionName &&
ContainedDeducedType && ContainedDeducedType->isUndeducedType())
return Found;
for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
UEnd = Record->conversion_end(); U != UEnd; ++U) {
FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
if (!ConvTemplate)
continue;
// When we're performing lookup for the purposes of redeclaration, just
// add the conversion function template. When we deduce template
// arguments for specializations, we'll end up unifying the return
// type of the new declaration with the type of the function template.
if (R.isForRedeclaration()) {
R.addDecl(ConvTemplate);
Found = true;
continue;
}
// C++ [temp.mem]p6:
// [...] For each such operator, if argument deduction succeeds
// (14.9.2.3), the resulting specialization is used as if found by
// name lookup.
//
// When referencing a conversion function for any purpose other than
// a redeclaration (such that we'll be building an expression with the
// result), perform template argument deduction and place the
// specialization into the result set. We do this to avoid forcing all
// callers to perform special deduction for conversion functions.
TemplateDeductionInfo Info(R.getNameLoc());
FunctionDecl *Specialization = nullptr;
const FunctionProtoType *ConvProto
= ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
assert(ConvProto && "Nonsensical conversion function template type");
// Compute the type of the function that we would expect the conversion
// function to have, if it were to match the name given.
// FIXME: Calling convention!
FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
EPI.ExceptionSpec = EST_None;
QualType ExpectedType = R.getSema().Context.getFunctionType(
R.getLookupName().getCXXNameType(), {}, EPI);
// Perform template argument deduction against the type that we would
// expect the function to have.
if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
Specialization, Info) ==
TemplateDeductionResult::Success) {
R.addDecl(Specialization);
Found = true;
}
}
return Found;
}
// Performs C++ unqualified lookup into the given file context.
static bool CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
const DeclContext *NS,
UnqualUsingDirectiveSet &UDirs) {
assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
// Perform direct name lookup into the LookupCtx.
bool Found = LookupDirect(S, R, NS);
// Perform direct name lookup into the namespaces nominated by the
// using directives whose common ancestor is this namespace.
for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
if (LookupDirect(S, R, UUE.getNominatedNamespace()))
Found = true;
R.resolveKind();
return Found;
}
static bool isNamespaceOrTranslationUnitScope(Scope *S) {
if (DeclContext *Ctx = S->getEntity())
return Ctx->isFileContext();
return false;
}
/// Find the outer declaration context from this scope. This indicates the
/// context that we should search up to (exclusive) before considering the
/// parent of the specified scope.
static DeclContext *findOuterContext(Scope *S) {
for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent())
if (DeclContext *DC = OuterS->getLookupEntity())
return DC;
return nullptr;
}
namespace {
/// An RAII object to specify that we want to find block scope extern
/// declarations.
struct FindLocalExternScope {
FindLocalExternScope(LookupResult &R)
: R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
Decl::IDNS_LocalExtern) {
R.setFindLocalExtern(R.getIdentifierNamespace() &
(Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator));
}
void restore() {
R.setFindLocalExtern(OldFindLocalExtern);
}
~FindLocalExternScope() {
restore();
}
LookupResult &R;
bool OldFindLocalExtern;
};
} // end anonymous namespace
bool Sema::CppLookupName(LookupResult &R, Scope *S) {
assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
DeclarationName Name = R.getLookupName();
Sema::LookupNameKind NameKind = R.getLookupKind();
// If this is the name of an implicitly-declared special member function,
// go through the scope stack to implicitly declare
if (isImplicitlyDeclaredMemberFunctionName(Name)) {
for (Scope *PreS = S; PreS; PreS = PreS->getParent())
if (DeclContext *DC = PreS->getEntity())
DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
}
// C++23 [temp.dep.general]p2:
// The component name of an unqualified-id is dependent if
// - it is a conversion-function-id whose conversion-type-id
// is dependent, or
// - it is operator= and the current class is a templated entity, or
// - the unqualified-id is the postfix-expression in a dependent call.
if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName &&
Name.getCXXNameType()->isDependentType()) {
R.setNotFoundInCurrentInstantiation();
return false;
}
// Implicitly declare member functions with the name we're looking for, if in
// fact we are in a scope where it matters.
Scope *Initial = S;
IdentifierResolver::iterator
I = IdResolver.begin(Name),
IEnd = IdResolver.end();
// First we lookup local scope.
// We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
// ...During unqualified name lookup (3.4.1), the names appear as if
// they were declared in the nearest enclosing namespace which contains
// both the using-directive and the nominated namespace.
// [Note: in this context, "contains" means "contains directly or
// indirectly".
//
// For example:
// namespace A { int i; }
// void foo() {
// int i;
// {
// using namespace A;
// ++i; // finds local 'i', A::i appears at global scope
// }
// }
//
UnqualUsingDirectiveSet UDirs(*this);
bool VisitedUsingDirectives = false;
bool LeftStartingScope = false;
// When performing a scope lookup, we want to find local extern decls.
FindLocalExternScope FindLocals(R);
for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
bool SearchNamespaceScope = true;
// Check whether the IdResolver has anything in this scope.
for (; I != IEnd && S->isDeclScope(*I); ++I) {
if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
if (NameKind == LookupRedeclarationWithLinkage &&
!(*I)->isTemplateParameter()) {
// If it's a template parameter, we still find it, so we can diagnose
// the invalid redeclaration.
// Determine whether this (or a previous) declaration is
// out-of-scope.
if (!LeftStartingScope && !Initial->isDeclScope(*I))
LeftStartingScope = true;
// If we found something outside of our starting scope that
// does not have linkage, skip it.
if (LeftStartingScope && !((*I)->hasLinkage())) {
R.setShadowed();
continue;
}
} else {
// We found something in this scope, we should not look at the
// namespace scope
SearchNamespaceScope = false;
}
R.addDecl(ND);
}
}
if (!SearchNamespaceScope) {
R.resolveKind();
if (S->isClassScope())
if (auto *Record = dyn_cast_if_present<CXXRecordDecl>(S->getEntity()))
R.setNamingClass(Record);
return true;
}
if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
// C++11 [class.friend]p11:
// If a friend declaration appears in a local class and the name
// specified is an unqualified name, a prior declaration is
// looked up without considering scopes that are outside the
// innermost enclosing non-class scope.
return false;
}
if (DeclContext *Ctx = S->getLookupEntity()) {
DeclContext *OuterCtx = findOuterContext(S);
for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
// We do not directly look into transparent contexts, since
// those entities will be found in the nearest enclosing
// non-transparent context.
if (Ctx->isTransparentContext())
continue;
// We do not look directly into function or method contexts,
// since all of the local variables and parameters of the
// function/method are present within the Scope.
if (Ctx->isFunctionOrMethod()) {
// If we have an Objective-C instance method, look for ivars
// in the corresponding interface.
if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
ObjCInterfaceDecl *ClassDeclared;
if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
Name.getAsIdentifierInfo(),
ClassDeclared)) {
if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
R.addDecl(ND);
R.resolveKind();
return true;
}
}
}
}
continue;
}
// If this is a file context, we need to perform unqualified name
// lookup considering using directives.
if (Ctx->isFileContext()) {
// If we haven't handled using directives yet, do so now.
if (!VisitedUsingDirectives) {
// Add using directives from this context up to the top level.
for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
if (UCtx->isTransparentContext())
continue;
UDirs.visit(UCtx, UCtx);
}
// Find the innermost file scope, so we can add using directives
// from local scopes.
Scope *InnermostFileScope = S;
while (InnermostFileScope &&
!isNamespaceOrTranslationUnitScope(InnermostFileScope))
InnermostFileScope = InnermostFileScope->getParent();
UDirs.visitScopeChain(Initial, InnermostFileScope);
UDirs.done();
VisitedUsingDirectives = true;
}
if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
R.resolveKind();
return true;
}
continue;
}
// Perform qualified name lookup into this context.
// FIXME: In some cases, we know that every name that could be found by
// this qualified name lookup will also be on the identifier chain. For
// example, inside a class without any base classes, we never need to
// perform qualified lookup because all of the members are on top of the
// identifier chain.
if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
return true;
}
}
}
// Stop if we ran out of scopes.
// FIXME: This really, really shouldn't be happening.
if (!S) return false;
// If we are looking for members, no need to look into global/namespace scope.
if (NameKind == LookupMemberName)
return false;
// Collect UsingDirectiveDecls in all scopes, and recursively all
// nominated namespaces by those using-directives.
//
// FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
// don't build it for each lookup!
if (!VisitedUsingDirectives) {
UDirs.visitScopeChain(Initial, S);
UDirs.done();
}
// If we're not performing redeclaration lookup, do not look for local
// extern declarations outside of a function scope.
if (!R.isForRedeclaration())
FindLocals.restore();
// Lookup namespace scope, and global scope.
// Unqualified name lookup in C++ requires looking into scopes
// that aren't strictly lexical, and therefore we walk through the
// context as well as walking through the scopes.
for (; S; S = S->getParent()) {
// Check whether the IdResolver has anything in this scope.
bool Found = false;
for (; I != IEnd && S->isDeclScope(*I); ++I) {
if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
// We found something. Look for anything else in our scope
// with this same name and in an acceptable identifier
// namespace, so that we can construct an overload set if we
// need to.
Found = true;
R.addDecl(ND);
}
}
if (Found && S->isTemplateParamScope()) {
R.resolveKind();
return true;
}
DeclContext *Ctx = S->getLookupEntity();
if (Ctx) {
DeclContext *OuterCtx = findOuterContext(S);
for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
// We do not directly look into transparent contexts, since
// those entities will be found in the nearest enclosing
// non-transparent context.
if (Ctx->isTransparentContext())
continue;
// If we have a context, and it's not a context stashed in the
// template parameter scope for an out-of-line definition, also
// look into that context.
if (!(Found && S->isTemplateParamScope())) {
assert(Ctx->isFileContext() &&
"We should have been looking only at file context here already.");
// Look into context considering using-directives.
if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
Found = true;
}
if (Found) {
R.resolveKind();
return true;
}
if (R.isForRedeclaration() && !Ctx->isTransparentContext())
return false;
}
}
if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
return false;
}
return !R.empty();
}
void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
if (auto *M = getCurrentModule())
Context.mergeDefinitionIntoModule(ND, M);
else
// We're not building a module; just make the definition visible.
ND->setVisibleDespiteOwningModule();
// If ND is a template declaration, make the template parameters
// visible too. They're not (necessarily) within a mergeable DeclContext.
if (auto *TD = dyn_cast<TemplateDecl>(ND))
for (auto *Param : *TD->getTemplateParameters())
makeMergedDefinitionVisible(Param);
// If we import a named module which contains a header, and then we include a
// header which contains a definition of enums, we will skip parsing the enums
// in the current TU. But we need to ensure the visibility of the enum
// contants, since they are able to be found with the parents of their
// parents.
if (auto *ED = dyn_cast<EnumDecl>(ND);
ED && ED->isFromGlobalModule() && !ED->isScoped()) {
for (auto *ECD : ED->enumerators()) {
ECD->setVisibleDespiteOwningModule();
DeclContext *RedeclCtx = ED->getDeclContext()->getRedeclContext();
if (RedeclCtx->lookup(ECD->getDeclName()).empty())
RedeclCtx->makeDeclVisibleInContext(ECD);
}
}
}
/// Find the module in which the given declaration was defined.
static Module *getDefiningModule(Sema &S, Decl *Entity) {
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
// If this function was instantiated from a template, the defining module is
// the module containing the pattern.
if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
Entity = Pattern;
} else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
Entity = Pattern;
} else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
if (auto *Pattern = ED->getTemplateInstantiationPattern())
Entity = Pattern;
} else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
Entity = Pattern;
}
// Walk up to the containing context. That might also have been instantiated
// from a template.
DeclContext *Context = Entity->getLexicalDeclContext();
if (Context->isFileContext())
return S.getOwningModule(Entity);
return getDefiningModule(S, cast<Decl>(Context));
}
llvm::DenseSet<Module*> &Sema::getLookupModules() {
unsigned N = CodeSynthesisContexts.size();
for (unsigned I = CodeSynthesisContextLookupModules.size();
I != N; ++I) {
Module *M = CodeSynthesisContexts[I].Entity ?
getDefiningModule(*this, CodeSynthesisContexts[I].Entity) :
nullptr;
if (M && !LookupModulesCache.insert(M).second)
M = nullptr;
CodeSynthesisContextLookupModules.push_back(M);
}
return LookupModulesCache;
}
bool Sema::isUsableModule(const Module *M) {
assert(M && "We shouldn't check nullness for module here");
// Return quickly if we cached the result.
if (UsableModuleUnitsCache.count(M))
return true;
// If M is the global module fragment of the current translation unit. So it
// should be usable.
// [module.global.frag]p1:
// The global module fragment can be used to provide declarations that are
// attached to the global module and usable within the module unit.
if (M == TheGlobalModuleFragment || M == TheImplicitGlobalModuleFragment) {
UsableModuleUnitsCache.insert(M);
return true;
}
// Otherwise, the global module fragment from other translation unit is not
// directly usable.
if (M->isExplicitGlobalModule())
return false;
Module *Current = getCurrentModule();
// If we're not parsing a module, we can't use all the declarations from
// another module easily.
if (!Current)
return false;
// For implicit global module, the decls in the same modules with the parent
// module should be visible to the decls in the implicit global module.
if (Current->isImplicitGlobalModule())
Current = Current->getTopLevelModule();
if (M->isImplicitGlobalModule())
M = M->getTopLevelModule();
// If M is the module we're parsing or M and the current module unit lives in
// the same module, M should be usable.
//
// Note: It should be fine to search the vector `ModuleScopes` linearly since
// it should be generally small enough. There should be rare module fragments
// in a named module unit.
if (llvm::count_if(ModuleScopes,
[&M](const ModuleScope &MS) { return MS.Module == M; }) ||
getASTContext().isInSameModule(M, Current)) {
UsableModuleUnitsCache.insert(M);
return true;
}
return false;
}
bool Sema::hasVisibleMergedDefinition(const NamedDecl *Def) {
for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
if (isModuleVisible(Merged))
return true;
return false;
}
bool Sema::hasMergedDefinitionInCurrentModule(const NamedDecl *Def) {
for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
if (isUsableModule(Merged))
return true;
return false;
}
template <typename ParmDecl>
static bool
hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D,
llvm::SmallVectorImpl<Module *> *Modules,
Sema::AcceptableKind Kind) {
if (!D->hasDefaultArgument())
return false;
llvm::SmallPtrSet<const ParmDecl *, 4> Visited;
while (D && Visited.insert(D).second) {
auto &DefaultArg = D->getDefaultArgStorage();
if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind))
return true;
if (!DefaultArg.isInherited() && Modules) {
auto *NonConstD = const_cast<ParmDecl*>(D);
Modules->push_back(S.getOwningModule(NonConstD));
}
// If there was a previous default argument, maybe its parameter is
// acceptable.
D = DefaultArg.getInheritedFrom();
}
return false;
}
bool Sema::hasAcceptableDefaultArgument(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules,
Sema::AcceptableKind Kind) {
if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind);
if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind);
return ::hasAcceptableDefaultArgument(
*this, cast<TemplateTemplateParmDecl>(D), Modules, Kind);
}
bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules) {
return hasAcceptableDefaultArgument(D, Modules,
Sema::AcceptableKind::Visible);
}
bool Sema::hasReachableDefaultArgument(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
return hasAcceptableDefaultArgument(D, Modules,
Sema::AcceptableKind::Reachable);
}
template <typename Filter>
static bool
hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules, Filter F,
Sema::AcceptableKind Kind) {
bool HasFilteredRedecls = false;
for (auto *Redecl : D->redecls()) {
auto *R = cast<NamedDecl>(Redecl);
if (!F(R))
continue;
if (S.isAcceptable(R, Kind))
return true;
HasFilteredRedecls = true;
if (Modules)
Modules->push_back(R->getOwningModule());
}
// Only return false if there is at least one redecl that is not filtered out.
if (HasFilteredRedecls)
return false;
return true;
}
static bool
hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules,
Sema::AcceptableKind Kind) {
return hasAcceptableDeclarationImpl(
S, D, Modules,
[](const NamedDecl *D) {
if (auto *RD = dyn_cast<CXXRecordDecl>(D))
return RD->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization;
if (auto *FD = dyn_cast<FunctionDecl>(D))
return FD->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization;
if (auto *VD = dyn_cast<VarDecl>(D))
return VD->getTemplateSpecializationKind() ==
TSK_ExplicitSpecialization;
llvm_unreachable("unknown explicit specialization kind");
},
Kind);
}
bool Sema::hasVisibleExplicitSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
return ::hasAcceptableExplicitSpecialization(*this, D, Modules,
Sema::AcceptableKind::Visible);
}
bool Sema::hasReachableExplicitSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
return ::hasAcceptableExplicitSpecialization(*this, D, Modules,
Sema::AcceptableKind::Reachable);
}
static bool
hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules,
Sema::AcceptableKind Kind) {
assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
"not a member specialization");
return hasAcceptableDeclarationImpl(
S, D, Modules,
[](const NamedDecl *D) {
// If the specialization is declared at namespace scope, then it's a
// member specialization declaration. If it's lexically inside the class
// definition then it was instantiated.
//
// FIXME: This is a hack. There should be a better way to determine
// this.
// FIXME: What about MS-style explicit specializations declared within a
// class definition?
return D->getLexicalDeclContext()->isFileContext();
},
Kind);
}
bool Sema::hasVisibleMemberSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
return hasAcceptableMemberSpecialization(*this, D, Modules,
Sema::AcceptableKind::Visible);
}
bool Sema::hasReachableMemberSpecialization(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
return hasAcceptableMemberSpecialization(*this, D, Modules,
Sema::AcceptableKind::Reachable);
}
/// Determine whether a declaration is acceptable to name lookup.
///
/// This routine determines whether the declaration D is acceptable in the
/// current lookup context, taking into account the current template
/// instantiation stack. During template instantiation, a declaration is
/// acceptable if it is acceptable from a module containing any entity on the
/// template instantiation path (by instantiating a template, you allow it to
/// see the declarations that your module can see, including those later on in
/// your module).
bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D,
Sema::AcceptableKind Kind) {
assert(!D->isUnconditionallyVisible() &&
"should not call this: not in slow case");
Module *DeclModule = SemaRef.getOwningModule(D);
assert(DeclModule && "hidden decl has no owning module");
// If the owning module is visible, the decl is acceptable.
if (SemaRef.isModuleVisible(DeclModule,
D->isInvisibleOutsideTheOwningModule()))
return true;
// Determine whether a decl context is a file context for the purpose of
// visibility/reachability. This looks through some (export and linkage spec)
// transparent contexts, but not others (enums).
auto IsEffectivelyFileContext = [](const DeclContext *DC) {
return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
isa<ExportDecl>(DC);
};
// If this declaration is not at namespace scope
// then it is acceptable if its lexical parent has a acceptable definition.
DeclContext *DC = D->getLexicalDeclContext();
if (DC && !IsEffectivelyFileContext(DC)) {
// For a parameter, check whether our current template declaration's
// lexical context is acceptable, not whether there's some other acceptable
// definition of it, because parameters aren't "within" the definition.
//
// In C++ we need to check for a acceptable definition due to ODR merging,
// and in C we must not because each declaration of a function gets its own
// set of declarations for tags in prototype scope.
bool AcceptableWithinParent;
if (D->isTemplateParameter()) {
bool SearchDefinitions = true;
if (const auto *DCD = dyn_cast<Decl>(DC)) {
if (const auto *TD = DCD->getDescribedTemplate()) {
TemplateParameterList *TPL = TD->getTemplateParameters();
auto Index = getDepthAndIndex(D).second;
SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D;
}
}
if (SearchDefinitions)
AcceptableWithinParent =
SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind);
else
AcceptableWithinParent =
isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind);
} else if (isa<ParmVarDecl>(D) ||
(isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
AcceptableWithinParent = isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind);
else if (D->isModulePrivate()) {
// A module-private declaration is only acceptable if an enclosing lexical
// parent was merged with another definition in the current module.
AcceptableWithinParent = false;
do {
if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
AcceptableWithinParent = true;
break;
}
DC = DC->getLexicalParent();
} while (!IsEffectivelyFileContext(DC));
} else {
AcceptableWithinParent =
SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind);
}
if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
Kind == Sema::AcceptableKind::Visible &&
// FIXME: Do something better in this case.
!SemaRef.getLangOpts().ModulesLocalVisibility) {
// Cache the fact that this declaration is implicitly visible because
// its parent has a visible definition.
D->setVisibleDespiteOwningModule();
}
return AcceptableWithinParent;
}
if (Kind == Sema::AcceptableKind::Visible)
return false;
assert(Kind == Sema::AcceptableKind::Reachable &&
"Additional Sema::AcceptableKind?");
return isReachableSlow(SemaRef, D);
}
bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
// The module might be ordinarily visible. For a module-private query, that
// means it is part of the current module.
if (ModulePrivate && isUsableModule(M))
return true;
// For a query which is not module-private, that means it is in our visible
// module set.
if (!ModulePrivate && VisibleModules.isVisible(M))
return true;
// Otherwise, it might be visible by virtue of the query being within a
// template instantiation or similar that is permitted to look inside M.
// Find the extra places where we need to look.
const auto &LookupModules = getLookupModules();
if (LookupModules.empty())
return false;
// If our lookup set contains the module, it's visible.
if (LookupModules.count(M))
return true;
// The global module fragments are visible to its corresponding module unit.
// So the global module fragment should be visible if the its corresponding
// module unit is visible.
if (M->isGlobalModule() && LookupModules.count(M->getTopLevelModule()))
return true;
// For a module-private query, that's everywhere we get to look.
if (ModulePrivate)
return false;
// Check whether M is transitively exported to an import of the lookup set.
return llvm::any_of(LookupModules, [&](const Module *LookupM) {
return LookupM->isModuleVisible(M);
});
}
// FIXME: Return false directly if we don't have an interface dependency on the
// translation unit containing D.
bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) {
assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n");
Module *DeclModule = SemaRef.getOwningModule(D);
assert(DeclModule && "hidden decl has no owning module");
// Entities in header like modules are reachable only if they're visible.
if (DeclModule->isHeaderLikeModule())
return false;
if (!D->isInAnotherModuleUnit())
return true;
// [module.reach]/p3:
// A declaration D is reachable from a point P if:
// ...
// - D is not discarded ([module.global.frag]), appears in a translation unit
// that is reachable from P, and does not appear within a private module
// fragment.
//
// A declaration that's discarded in the GMF should be module-private.
if (D->isModulePrivate())
return false;
Module *DeclTopModule = DeclModule->getTopLevelModule();
// [module.reach]/p1
// A translation unit U is necessarily reachable from a point P if U is a
// module interface unit on which the translation unit containing P has an
// interface dependency, or the translation unit containing P imports U, in
// either case prior to P ([module.import]).
//
// [module.import]/p10
// A translation unit has an interface dependency on a translation unit U if
// it contains a declaration (possibly a module-declaration) that imports U
// or if it has an interface dependency on a translation unit that has an
// interface dependency on U.
//
// So we could conclude the module unit U is necessarily reachable if:
// (1) The module unit U is module interface unit.
// (2) The current unit has an interface dependency on the module unit U.
//
// Here we only check for the first condition. Since we couldn't see
// DeclModule if it isn't (transitively) imported.
if (DeclTopModule->isModuleInterfaceUnit())
return true;
// [module.reach]/p1,2
// A translation unit U is necessarily reachable from a point P if U is a
// module interface unit on which the translation unit containing P has an
// interface dependency, or the translation unit containing P imports U, in
// either case prior to P
//
// Additional translation units on
// which the point within the program has an interface dependency may be
// considered reachable, but it is unspecified which are and under what
// circumstances.
Module *CurrentM = SemaRef.getCurrentModule();
// Directly imported module are necessarily reachable.
// Since we can't export import a module implementation partition unit, we
// don't need to count for Exports here.
if (CurrentM && CurrentM->getTopLevelModule()->Imports.count(DeclTopModule))
return true;
// Then we treat all module implementation partition unit as unreachable.
return false;
}
bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) {
return LookupResult::isAcceptable(*this, const_cast<NamedDecl *>(D), Kind);
}
bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
// FIXME: If there are both visible and hidden declarations, we need to take
// into account whether redeclaration is possible. Example:
//
// Non-imported module:
// int f(T); // #1
// Some TU:
// static int f(U); // #2, not a redeclaration of #1
// int f(T); // #3, finds both, should link with #1 if T != U, but
// // with #2 if T == U; neither should be ambiguous.
for (auto *D : R) {
if (isVisible(D))
return true;
assert(D->isExternallyDeclarable() &&
"should not have hidden, non-externally-declarable result here");
}
// This function is called once "New" is essentially complete, but before a
// previous declaration is attached. We can't query the linkage of "New" in
// general, because attaching the previous declaration can change the
// linkage of New to match the previous declaration.
//
// However, because we've just determined that there is no *visible* prior
// declaration, we can compute the linkage here. There are two possibilities:
//
// * This is not a redeclaration; it's safe to compute the linkage now.
//
// * This is a redeclaration of a prior declaration that is externally
// redeclarable. In that case, the linkage of the declaration is not
// changed by attaching the prior declaration, because both are externally
// declarable (and thus ExternalLinkage or VisibleNoLinkage).
//
// FIXME: This is subtle and fragile.
return New->isExternallyDeclarable();
}
/// Retrieve the visible declaration corresponding to D, if any.
///
/// This routine determines whether the declaration D is visible in the current
/// module, with the current imports. If not, it checks whether any
/// redeclaration of D is visible, and if so, returns that declaration.
///
/// \returns D, or a visible previous declaration of D, whichever is more recent
/// and visible. If no declaration of D is visible, returns null.
static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D,
unsigned IDNS) {
assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case");
for (auto *RD : D->redecls()) {
// Don't bother with extra checks if we already know this one isn't visible.
if (RD == D)
continue;
auto ND = cast<NamedDecl>(RD);
// FIXME: This is wrong in the case where the previous declaration is not
// visible in the same scope as D. This needs to be done much more
// carefully.
if (ND->isInIdentifierNamespace(IDNS) &&
LookupResult::isAvailableForLookup(SemaRef, ND))
return ND;
}
return nullptr;
}
bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
llvm::SmallVectorImpl<Module *> *Modules) {
assert(!isVisible(D) && "not in slow case");
return hasAcceptableDeclarationImpl(
*this, D, Modules, [](const NamedDecl *) { return true; },
Sema::AcceptableKind::Visible);
}
bool Sema::hasReachableDeclarationSlow(
const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
assert(!isReachable(D) && "not in slow case");
return hasAcceptableDeclarationImpl(
*this, D, Modules, [](const NamedDecl *) { return true; },
Sema::AcceptableKind::Reachable);
}
NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
// Namespaces are a bit of a special case: we expect there to be a lot of
// redeclarations of some namespaces, all declarations of a namespace are
// essentially interchangeable, all declarations are found by name lookup
// if any is, and namespaces are never looked up during template
// instantiation. So we benefit from caching the check in this case, and
// it is correct to do so.
auto *Key = ND->getCanonicalDecl();
if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
return Acceptable;
auto *Acceptable = isVisible(getSema(), Key)
? Key
: findAcceptableDecl(getSema(), Key, IDNS);
if (Acceptable)
getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
return Acceptable;
}
return findAcceptableDecl(getSema(), D, IDNS);
}
bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) {
// If this declaration is already visible, return it directly.
if (D->isUnconditionallyVisible())
return true;
// During template instantiation, we can refer to hidden declarations, if
// they were visible in any module along the path of instantiation.
return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Visible);
}
bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) {
if (D->isUnconditionallyVisible())
return true;
return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Reachable);
}
bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) {
// We should check the visibility at the callsite already.
if (isVisible(SemaRef, ND))
return true;
// Deduction guide lives in namespace scope generally, but it is just a
// hint to the compilers. What we actually lookup for is the generated member
// of the corresponding template. So it is sufficient to check the
// reachability of the template decl.
if (auto *DeductionGuide = ND->getDeclName().getCXXDeductionGuideTemplate())
return SemaRef.hasReachableDefinition(DeductionGuide);
// FIXME: The lookup for allocation function is a standalone process.
// (We can find the logics in Sema::FindAllocationFunctions)
//
// Such structure makes it a problem when we instantiate a template
// declaration using placement allocation function if the placement
// allocation function is invisible.
// (See https://github.com/llvm/llvm-project/issues/59601)
//
// Here we workaround it by making the placement allocation functions
// always acceptable. The downside is that we can't diagnose the direct
// use of the invisible placement allocation functions. (Although such uses
// should be rare).
if (auto *FD = dyn_cast<FunctionDecl>(ND);
FD && FD->isReservedGlobalPlacementOperator())
return true;
auto *DC = ND->getDeclContext();
// If ND is not visible and it is at namespace scope, it shouldn't be found
// by name lookup.
if (DC->isFileContext())
return false;
// [module.interface]p7
// Class and enumeration member names can be found by name lookup in any
// context in which a definition of the type is reachable.
//
// NOTE: The above wording may be problematic. See
// https://github.com/llvm/llvm-project/issues/131058 But it is much complext
// to adjust it in Sema's lookup process. Now we hacked it in ASTWriter. See
// the comments in ASTDeclContextNameLookupTrait::getLookupVisibility.
if (auto *TD = dyn_cast<TagDecl>(DC))
return SemaRef.hasReachableDefinition(TD);
return false;
}
bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation,
bool ForceNoCPlusPlus) {
DeclarationName Name = R.getLookupName();
if (!Name) return false;
LookupNameKind NameKind = R.getLookupKind();
if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) {
// Unqualified name lookup in C/Objective-C is purely lexical, so
// search in the declarations attached to the name.
if (NameKind == Sema::LookupRedeclarationWithLinkage) {
// Find the nearest non-transparent declaration scope.
while (!(S->getFlags() & Scope::DeclScope) ||
(S->getEntity() && S->getEntity()->isTransparentContext()))
S = S->getParent();
}
// When performing a scope lookup, we want to find local extern decls.
FindLocalExternScope FindLocals(R);
// Scan up the scope chain looking for a decl that matches this
// identifier that is in the appropriate namespace. This search
// should not take long, as shadowing of names is uncommon, and
// deep shadowing is extremely uncommon.
bool LeftStartingScope = false;
for (IdentifierResolver::iterator I = IdResolver.begin(Name),
IEnd = IdResolver.end();
I != IEnd; ++I)
if (NamedDecl *D = R.getAcceptableDecl(*I)) {
if (NameKind == LookupRedeclarationWithLinkage) {
// Determine whether this (or a previous) declaration is
// out-of-scope.
if (!LeftStartingScope && !S->isDeclScope(*I))
LeftStartingScope = true;
// If we found something outside of our starting scope that
// does not have linkage, skip it.
if (LeftStartingScope && !((*I)->hasLinkage())) {
R.setShadowed();
continue;
}
}
else if (NameKind == LookupObjCImplicitSelfParam &&
!isa<ImplicitParamDecl>(*I))
continue;
R.addDecl(D);
// Check whether there are any other declarations with the same name
// and in the same scope.
if (I != IEnd) {
// Find the scope in which this declaration was declared (if it
// actually exists in a Scope).
while (S && !S->isDeclScope(D))
S = S->getParent();
// If the scope containing the declaration is the translation unit,
// then we'll need to perform our checks based on the matching
// DeclContexts rather than matching scopes.
if (S && isNamespaceOrTranslationUnitScope(S))
S = nullptr;
// Compute the DeclContext, if we need it.
DeclContext *DC = nullptr;
if (!S)
DC = (*I)->getDeclContext()->getRedeclContext();
IdentifierResolver::iterator LastI = I;
for (++LastI; LastI != IEnd; ++LastI) {
if (S) {
// Match based on scope.
if (!S->isDeclScope(*LastI))
break;
} else {
// Match based on DeclContext.
DeclContext *LastDC
= (*LastI)->getDeclContext()->getRedeclContext();
if (!LastDC->Equals(DC))
break;
}
// If the declaration is in the right namespace and visible, add it.
if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
R.addDecl(LastD);
}
R.resolveKind();
}
return true;
}
} else {
// Perform C++ unqualified name lookup.
if (CppLookupName(R, S))
return true;
}
// If we didn't find a use of this identifier, and if the identifier
// corresponds to a compiler builtin, create the decl object for the builtin
// now, injecting it into translation unit scope, and return it.
if (AllowBuiltinCreation && LookupBuiltin(R))
return true;
// If we didn't find a use of this identifier, the ExternalSource
// may be able to handle the situation.
// Note: some lookup failures are expected!
// See e.g. R.isForRedeclaration().
return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
}
/// Perform qualified name lookup in the namespaces nominated by
/// using directives by the given context.
///
/// C++98 [namespace.qual]p2:
/// Given X::m (where X is a user-declared namespace), or given \::m
/// (where X is the global namespace), let S be the set of all
/// declarations of m in X and in the transitive closure of all
/// namespaces nominated by using-directives in X and its used
/// namespaces, except that using-directives are ignored in any
/// namespace, including X, directly containing one or more
/// declarations of m. No namespace is searched more than once in
/// the lookup of a name. If S is the empty set, the program is
/// ill-formed. Otherwise, if S has exactly one member, or if the
/// context of the reference is a using-declaration
/// (namespace.udecl), S is the required set of declarations of
/// m. Otherwise if the use of m is not one that allows a unique
/// declaration to be chosen from S, the program is ill-formed.
///
/// C++98 [namespace.qual]p5:
/// During the lookup of a qualified namespace member name, if the
/// lookup finds more than one declaration of the member, and if one
/// declaration introduces a class name or enumeration name and the
/// other declarations either introduce the same object, the same
/// enumerator or a set of functions, the non-type name hides the
/// class or enumeration name if and only if the declarations are
/// from the same namespace; otherwise (the declarations are from
/// different namespaces), the program is ill-formed.
static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
DeclContext *StartDC) {
assert(StartDC->isFileContext() && "start context is not a file context");
// We have not yet looked into these namespaces, much less added
// their "using-children" to the queue.
SmallVector<NamespaceDecl*, 8> Queue;
// We have at least added all these contexts to the queue.
llvm::SmallPtrSet<DeclContext*, 8> Visited;
Visited.insert(StartDC);
// We have already looked into the initial namespace; seed the queue
// with its using-children.
for (auto *I : StartDC->using_directives()) {
NamespaceDecl *ND = I->getNominatedNamespace()->getFirstDecl();
if (S.isVisible(I) && Visited.insert(ND).second)
Queue.push_back(ND);
}
// The easiest way to implement the restriction in [namespace.qual]p5
// is to check whether any of the individual results found a tag
// and, if so, to declare an ambiguity if the final result is not
// a tag.
bool FoundTag = false;
bool FoundNonTag = false;
LookupResult LocalR(LookupResult::Temporary, R);
bool Found = false;
while (!Queue.empty()) {
NamespaceDecl *ND = Queue.pop_back_val();
// We go through some convolutions here to avoid copying results
// between LookupResults.
bool UseLocal = !R.empty();
LookupResult &DirectR = UseLocal ? LocalR : R;
bool FoundDirect = LookupDirect(S, DirectR, ND);
if (FoundDirect) {
// First do any local hiding.
DirectR.resolveKind();
// If the local result is a tag, remember that.
if (DirectR.isSingleTagDecl())
FoundTag = true;
else
FoundNonTag = true;
// Append the local results to the total results if necessary.
if (UseLocal) {
R.addAllDecls(LocalR);
LocalR.clear();
}
}
// If we find names in this namespace, ignore its using directives.
if (FoundDirect) {
Found = true;
continue;
}
for (auto *I : ND->using_directives()) {
NamespaceDecl *Nom = I->getNominatedNamespace();
if (S.isVisible(I) && Visited.insert(Nom).second)
Queue.push_back(Nom);
}
}
if (Found) {
if (FoundTag && FoundNonTag)
R.setAmbiguousQualifiedTagHiding();
else
R.resolveKind();
}
return Found;
}
bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
bool InUnqualifiedLookup) {
assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
if (!R.getLookupName())
return false;
#ifndef NDEBUG
// Make sure that the declaration context is complete.
if (const auto *TD = dyn_cast<TagDecl>(LookupCtx);
TD && !TD->isDependentType() && TD->getDefinition() == nullptr)
llvm_unreachable("Declaration context must already be complete!");
#endif
struct QualifiedLookupInScope {
bool oldVal;
DeclContext *Context;
// Set flag in DeclContext informing debugger that we're looking for qualified name
QualifiedLookupInScope(DeclContext *ctx)
: oldVal(ctx->shouldUseQualifiedLookup()), Context(ctx) {
ctx->setUseQualifiedLookup();
}
~QualifiedLookupInScope() {
Context->setUseQualifiedLookup(oldVal);
}
} QL(LookupCtx);
CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
// FIXME: Per [temp.dep.general]p2, an unqualified name is also dependent
// if it's a dependent conversion-function-id or operator= where the current
// class is a templated entity. This should be handled in LookupName.
if (!InUnqualifiedLookup && !R.isForRedeclaration()) {
// C++23 [temp.dep.type]p5:
// A qualified name is dependent if
// - it is a conversion-function-id whose conversion-type-id
// is dependent, or
// - [...]
// - its lookup context is the current instantiation and it
// is operator=, or
// - [...]
if (DeclarationName Name = R.getLookupName();
Name.getNameKind() == DeclarationName::CXXConversionFunctionName &&
Name.getCXXNameType()->isDependentType()) {
R.setNotFoundInCurrentInstantiation();
return false;
}
}
if (LookupDirect(*this, R, LookupCtx)) {
R.resolveKind();
if (LookupRec)
R.setNamingClass(LookupRec);
return true;
}
// Don't descend into implied contexts for redeclarations.
// C++98 [namespace.qual]p6:
// In a declaration for a namespace member in which the
// declarator-id is a qualified-id, given that the qualified-id
// for the namespace member has the form
// nested-name-specifier unqualified-id
// the unqualified-id shall name a member of the namespace
// designated by the nested-name-specifier.
// See also [class.mfct]p5 and [class.static.data]p2.
if (R.isForRedeclaration())
return false;
// If this is a namespace, look it up in the implied namespaces.
if (LookupCtx->isFileContext())
return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
// If this isn't a C++ class, we aren't allowed to look into base
// classes, we're done.
if (!LookupRec || !LookupRec->getDefinition())
return false;
// We're done for lookups that can never succeed for C++ classes.
if (R.getLookupKind() == LookupOperatorName ||
R.getLookupKind() == LookupNamespaceName ||
R.getLookupKind() == LookupObjCProtocolName ||
R.getLookupKind() == LookupLabel)
return false;
// If we're performing qualified name lookup into a dependent class,
// then we are actually looking into a current instantiation. If we have any
// dependent base classes, then we either have to delay lookup until
// template instantiation time (at which point all bases will be available)
// or we have to fail.
if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
LookupRec->hasAnyDependentBases()) {
R.setNotFoundInCurrentInstantiation();
return false;
}
// Perform lookup into our base classes.
DeclarationName Name = R.getLookupName();
unsigned IDNS = R.getIdentifierNamespace();
// Look for this member in our base classes.
auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier,
CXXBasePath &Path) -> bool {
CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
// Drop leading non-matching lookup results from the declaration list so
// we don't need to consider them again below.
for (Path.Decls = BaseRecord->lookup(Name).begin();
Path.Decls != Path.Decls.end(); ++Path.Decls) {
if ((*Path.Decls)->isInIdentifierNamespace(IDNS))
return true;
}
return false;
};
CXXBasePaths Paths;
Paths.setOrigin(LookupRec);
if (!LookupRec->lookupInBases(BaseCallback, Paths))
return false;
R.setNamingClass(LookupRec);
// C++ [class.member.lookup]p2:
// [...] If the resulting set of declarations are not all from
// sub-objects of the same type, or the set has a nonstatic member
// and includes members from distinct sub-objects, there is an
// ambiguity and the program is ill-formed. Otherwise that set is
// the result of the lookup.
QualType SubobjectType;
int SubobjectNumber = 0;
AccessSpecifier SubobjectAccess = AS_none;
// Check whether the given lookup result contains only static members.
auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) {
for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I)
if ((*I)->isInIdentifierNamespace(IDNS) && (*I)->isCXXInstanceMember())
return false;
return true;
};
bool TemplateNameLookup = R.isTemplateNameLookup();
// Determine whether two sets of members contain the same members, as
// required by C++ [class.member.lookup]p6.
auto HasSameDeclarations = [&](DeclContext::lookup_iterator A,
DeclContext::lookup_iterator B) {
using Iterator = DeclContextLookupResult::iterator;
using Result = const void *;
auto Next = [&](Iterator &It, Iterator End) -> Result {
while (It != End) {
NamedDecl *ND = *It++;
if (!ND->isInIdentifierNamespace(IDNS))
continue;
// C++ [temp.local]p3:
// A lookup that finds an injected-class-name (10.2) can result in
// an ambiguity in certain cases (for example, if it is found in
// more than one base class). If all of the injected-class-names
// that are found refer to specializations of the same class
// template, and if the name is used as a template-name, the
// reference refers to the class template itself and not a
// specialization thereof, and is not ambiguous.
if (TemplateNameLookup)
if (auto *TD = getAsTemplateNameDecl(ND))
ND = TD;
// C++ [class.member.lookup]p3:
// type declarations (including injected-class-names) are replaced by
// the types they designate
if (const TypeDecl *TD = dyn_cast<TypeDecl>(ND->getUnderlyingDecl()))
return Context.getCanonicalTypeDeclType(TD).getAsOpaquePtr();
return ND->getUnderlyingDecl()->getCanonicalDecl();
}
return nullptr;
};
// We'll often find the declarations are in the same order. Handle this
// case (and the special case of only one declaration) efficiently.
Iterator AIt = A, BIt = B, AEnd, BEnd;
while (true) {
Result AResult = Next(AIt, AEnd);
Result BResult = Next(BIt, BEnd);
if (!AResult && !BResult)
return true;
if (!AResult || !BResult)
return false;
if (AResult != BResult) {
// Found a mismatch; carefully check both lists, accounting for the
// possibility of declarations appearing more than once.
llvm::SmallDenseMap<Result, bool, 32> AResults;
for (; AResult; AResult = Next(AIt, AEnd))
AResults.insert({AResult, /*FoundInB*/false});
unsigned Found = 0;
for (; BResult; BResult = Next(BIt, BEnd)) {
auto It = AResults.find(BResult);
if (It == AResults.end())
return false;
if (!It->second) {
It->second = true;
++Found;
}
}
return AResults.size() == Found;
}
}
};
for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
Path != PathEnd; ++Path) {
const CXXBasePathElement &PathElement = Path->back();
// Pick the best (i.e. most permissive i.e. numerically lowest) access
// across all paths.
SubobjectAccess = std::min(SubobjectAccess, Path->Access);
// Determine whether we're looking at a distinct sub-object or not.
if (SubobjectType.isNull()) {
// This is the first subobject we've looked at. Record its type.
SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
SubobjectNumber = PathElement.SubobjectNumber;
continue;
}
if (SubobjectType !=
Context.getCanonicalType(PathElement.Base->getType())) {
// We found members of the given name in two subobjects of
// different types. If the declaration sets aren't the same, this
// lookup is ambiguous.
//
// FIXME: The language rule says that this applies irrespective of
// whether the sets contain only static members.
if (HasOnlyStaticMembers(Path->Decls) &&
HasSameDeclarations(Paths.begin()->Decls, Path->Decls))
continue;
R.setAmbiguousBaseSubobjectTypes(Paths);
return true;
}
// FIXME: This language rule no longer exists. Checking for ambiguous base
// subobjects should be done as part of formation of a class member access
// expression (when converting the object parameter to the member's type).
if (SubobjectNumber != PathElement.SubobjectNumber) {
// We have a different subobject of the same type.
// C++ [class.member.lookup]p5:
// A static member, a nested type or an enumerator defined in
// a base class T can unambiguously be found even if an object
// has more than one base class subobject of type T.
if (HasOnlyStaticMembers(Path->Decls))
continue;
// We have found a nonstatic member name in multiple, distinct
// subobjects. Name lookup is ambiguous.
R.setAmbiguousBaseSubobjects(Paths);
return true;
}
}
// Lookup in a base class succeeded; return these results.
for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end();
I != E; ++I) {
AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
(*I)->getAccess());
if (NamedDecl *ND = R.getAcceptableDecl(*I))
R.addDecl(ND, AS);
}
R.resolveKind();
return true;
}
bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
CXXScopeSpec &SS) {
NestedNameSpecifier Qualifier = SS.getScopeRep();
if (Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
return LookupInSuper(R, Qualifier.getAsMicrosoftSuper());
return LookupQualifiedName(R, LookupCtx);
}
bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
QualType ObjectType, bool AllowBuiltinCreation,
bool EnteringContext) {
// When the scope specifier is invalid, don't even look for anything.
if (SS && SS->isInvalid())
return false;
// Determine where to perform name lookup
DeclContext *DC = nullptr;
bool IsDependent = false;
if (!ObjectType.isNull()) {
// This nested-name-specifier occurs in a member access expression, e.g.,
// x->B::f, and we are looking into the type of the object.
assert((!SS || SS->isEmpty()) &&
"ObjectType and scope specifier cannot coexist");
DC = computeDeclContext(ObjectType);
IsDependent = !DC && ObjectType->isDependentType();
assert(((!DC && ObjectType->isDependentType()) ||
!ObjectType->isIncompleteType() || !ObjectType->getAs<TagType>() ||
ObjectType->castAs<TagType>()
->getOriginalDecl()
->isEntityBeingDefined()) &&
"Caller should have completed object type");
} else if (SS && SS->isNotEmpty()) {
// This nested-name-specifier occurs after another nested-name-specifier,
// so long into the context associated with the prior nested-name-specifier.
if ((DC = computeDeclContext(*SS, EnteringContext))) {
// The declaration context must be complete.
if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
return false;
R.setContextRange(SS->getRange());
// FIXME: '__super' lookup semantics could be implemented by a
// LookupResult::isSuperLookup flag which skips the initial search of
// the lookup context in LookupQualified.
if (NestedNameSpecifier Qualifier = SS->getScopeRep();
Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
return LookupInSuper(R, Qualifier.getAsMicrosoftSuper());
}
IsDependent = !DC && isDependentScopeSpecifier(*SS);
} else {
// Perform unqualified name lookup starting in the given scope.
return LookupName(R, S, AllowBuiltinCreation);
}
// If we were able to compute a declaration context, perform qualified name
// lookup in that context.
if (DC)
return LookupQualifiedName(R, DC);
else if (IsDependent)
// We could not resolve the scope specified to a specific declaration
// context, which means that SS refers to an unknown specialization.
// Name lookup can't find anything in this case.
R.setNotFoundInCurrentInstantiation();
return false;
}
bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
// The access-control rules we use here are essentially the rules for
// doing a lookup in Class that just magically skipped the direct
// members of Class itself. That is, the naming class is Class, and the
// access includes the access of the base.
for (const auto &BaseSpec : Class->bases()) {
auto *RD = BaseSpec.getType()->castAsCXXRecordDecl();
LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
Result.setBaseObjectType(Context.getCanonicalTagType(Class));
LookupQualifiedName(Result, RD);
// Copy the lookup results into the target, merging the base's access into
// the path access.
for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
R.addDecl(I.getDecl(),
CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
I.getAccess()));
}
Result.suppressDiagnostics();
}
R.resolveKind();
R.setNamingClass(Class);
return !R.empty();
}
void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
DeclarationName Name = Result.getLookupName();
SourceLocation NameLoc = Result.getNameLoc();
SourceRange LookupRange = Result.getContextRange();
switch (Result.getAmbiguityKind()) {
case LookupAmbiguityKind::AmbiguousBaseSubobjects: {
CXXBasePaths *Paths = Result.getBasePaths();
QualType SubobjectType = Paths->front().back().Base->getType();
Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
<< Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
<< LookupRange;
DeclContext::lookup_iterator Found = Paths->front().Decls;
while (isa<CXXMethodDecl>(*Found) &&
cast<CXXMethodDecl>(*Found)->isStatic())
++Found;
Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
break;
}
case LookupAmbiguityKind::AmbiguousBaseSubobjectTypes: {
Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
<< Name << LookupRange;
CXXBasePaths *Paths = Result.getBasePaths();
std::set<const NamedDecl *> DeclsPrinted;
for (CXXBasePaths::paths_iterator Path = Paths->begin(),
PathEnd = Paths->end();
Path != PathEnd; ++Path) {
const NamedDecl *D = *Path->Decls;
if (!D->isInIdentifierNamespace(Result.getIdentifierNamespace()))
continue;
if (DeclsPrinted.insert(D).second) {
if (const auto *TD = dyn_cast<TypedefNameDecl>(D->getUnderlyingDecl()))
Diag(D->getLocation(), diag::note_ambiguous_member_type_found)
<< TD->getUnderlyingType();
else if (const auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
Diag(D->getLocation(), diag::note_ambiguous_member_type_found)
<< Context.getTypeDeclType(TD);
else
Diag(D->getLocation(), diag::note_ambiguous_member_found);
}
}
break;
}
case LookupAmbiguityKind::AmbiguousTagHiding: {
Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
for (auto *D : Result)
if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
TagDecls.insert(TD);
Diag(TD->getLocation(), diag::note_hidden_tag);
}
for (auto *D : Result)
if (!isa<TagDecl>(D))
Diag(D->getLocation(), diag::note_hiding_object);
// For recovery purposes, go ahead and implement the hiding.
LookupResult::Filter F = Result.makeFilter();
while (F.hasNext()) {
if (TagDecls.count(F.next()))
F.erase();
}
F.done();
break;
}
case LookupAmbiguityKind::AmbiguousReferenceToPlaceholderVariable: {
Diag(NameLoc, diag::err_using_placeholder_variable) << Name << LookupRange;
DeclContext *DC = nullptr;
for (auto *D : Result) {
Diag(D->getLocation(), diag::note_reference_placeholder) << D;
if (DC != nullptr && DC != D->getDeclContext())
break;
DC = D->getDeclContext();
}
break;
}
case LookupAmbiguityKind::AmbiguousReference: {
Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
for (auto *D : Result)
Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
break;
}
}
}
namespace {
struct AssociatedLookup {
AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
Sema::AssociatedNamespaceSet &Namespaces,
Sema::AssociatedClassSet &Classes)
: S(S), Namespaces(Namespaces), Classes(Classes),
InstantiationLoc(InstantiationLoc) {
}
bool addClassTransitive(CXXRecordDecl *RD) {
Classes.insert(RD);
return ClassesTransitive.insert(RD);
}
Sema &S;
Sema::AssociatedNamespaceSet &Namespaces;
Sema::AssociatedClassSet &Classes;
SourceLocation InstantiationLoc;
private:
Sema::AssociatedClassSet ClassesTransitive;
};
} // end anonymous namespace
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
// Given the declaration context \param Ctx of a class, class template or
// enumeration, add the associated namespaces to \param Namespaces as described
// in [basic.lookup.argdep]p2.
static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
DeclContext *Ctx) {
// The exact wording has been changed in C++14 as a result of
// CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
// to all language versions since it is possible to return a local type
// from a lambda in C++11.
//
// C++14 [basic.lookup.argdep]p2:
// If T is a class type [...]. Its associated namespaces are the innermost
// enclosing namespaces of its associated classes. [...]
//
// If T is an enumeration type, its associated namespace is the innermost
// enclosing namespace of its declaration. [...]
// We additionally skip inline namespaces. The innermost non-inline namespace
// contains all names of all its nested inline namespaces anyway, so we can
// replace the entire inline namespace tree with its root.
while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
Ctx = Ctx->getParent();
// Actually it is fine to always do `Namespaces.insert(Ctx);` simply. But it
// may cause more allocations in Namespaces and more unnecessary lookups. So
// we'd like to insert the representative namespace only.
DeclContext *PrimaryCtx = Ctx->getPrimaryContext();
Decl *PrimaryD = cast<Decl>(PrimaryCtx);
Decl *D = cast<Decl>(Ctx);
ASTContext &AST = D->getASTContext();
// TODO: Technically it is better to insert one namespace per module. e.g.,
//
// ```
// //--- first.cppm
// export module first;
// namespace ns { ... } // first namespace
//
// //--- m-partA.cppm
// export module m:partA;
// import first;
//
// namespace ns { ... }
// namespace ns { ... }
//
// //--- m-partB.cppm
// export module m:partB;
// import first;
// import :partA;
//
// namespace ns { ... }
// namespace ns { ... }
//
// ...
//
// //--- m-partN.cppm
// export module m:partN;
// import first;
// import :partA;
// ...
// import :part$(N-1);
//
// namespace ns { ... }
// namespace ns { ... }
//
// consume(ns::any_decl); // the lookup
// ```
//
// We should only insert once for all namespaces in module m.
if (D->isInNamedModule() &&
!AST.isInSameModule(D->getOwningModule(), PrimaryD->getOwningModule()))
Namespaces.insert(Ctx);
else
Namespaces.insert(PrimaryCtx);
}
// Add the associated classes and namespaces for argument-dependent
// lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
const TemplateArgument &Arg) {
// C++ [basic.lookup.argdep]p2, last bullet:
// -- [...] ;
switch (Arg.getKind()) {
case TemplateArgument::Null:
break;
case TemplateArgument::Type:
// [...] the namespaces and classes associated with the types of the
// template arguments provided for template type parameters (excluding
// template template parameters)
addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
break;
case TemplateArgument::Template:
case TemplateArgument::TemplateExpansion: {
// [...] the namespaces in which any template template arguments are
// defined; and the classes in which any member templates used as
// template template arguments are defined.
TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
if (ClassTemplateDecl *ClassTemplate
= dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
DeclContext *Ctx = ClassTemplate->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
}
break;
}
case TemplateArgument::Declaration:
case TemplateArgument::Integral:
case TemplateArgument::Expression:
case TemplateArgument::NullPtr:
case TemplateArgument::StructuralValue:
// [Note: non-type template arguments do not contribute to the set of
// associated namespaces. ]
break;
case TemplateArgument::Pack:
for (const auto &P : Arg.pack_elements())
addAssociatedClassesAndNamespaces(Result, P);
break;
}
}
// Add the associated classes and namespaces for argument-dependent lookup
// with an argument of class type (C++ [basic.lookup.argdep]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
CXXRecordDecl *Class) {
// Just silently ignore anything whose name is __va_list_tag.
if (Class->getDeclName() == Result.S.VAListTagName)
return;
// C++ [basic.lookup.argdep]p2:
// [...]
// -- If T is a class type (including unions), its associated
// classes are: the class itself; the class of which it is a
// member, if any; and its direct and indirect base classes.
// Its associated namespaces are the innermost enclosing
// namespaces of its associated classes.
// Add the class of which it is a member, if any.
DeclContext *Ctx = Class->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
// -- If T is a template-id, its associated namespaces and classes are
// the namespace in which the template is defined; for member
// templates, the member template's class; the namespaces and classes
// associated with the types of the template arguments provided for
// template type parameters (excluding template template parameters); the
// namespaces in which any template template arguments are defined; and
// the classes in which any member templates used as template template
// arguments are defined. [Note: non-type template arguments do not
// contribute to the set of associated namespaces. ]
if (ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this class.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
}
// Add the class itself. If we've already transitively visited this class,
// we don't need to visit base classes.
if (!Result.addClassTransitive(Class))
return;
// Only recurse into base classes for complete types.
if (!Result.S.isCompleteType(Result.InstantiationLoc,
Result.S.Context.getCanonicalTagType(Class)))
return;
// Add direct and indirect base classes along with their associated
// namespaces.
SmallVector<CXXRecordDecl *, 32> Bases;
Bases.push_back(Class);
while (!Bases.empty()) {
// Pop this class off the stack.
Class = Bases.pop_back_val();
// Visit the base classes.
for (const auto &Base : Class->bases()) {
CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
// In dependent contexts, we do ADL twice, and the first time around,
// the base type might be a dependent TemplateSpecializationType, or a
// TemplateTypeParmType. If that happens, simply ignore it.
// FIXME: If we want to support export, we probably need to add the
// namespace of the template in a TemplateSpecializationType, or even
// the classes and namespaces of known non-dependent arguments.
if (!BaseDecl)
continue;
if (Result.addClassTransitive(BaseDecl)) {
// Find the associated namespace for this base class.
DeclContext *BaseCtx = BaseDecl->getDeclContext();
CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
// Make sure we visit the bases of this base class.
if (!BaseDecl->bases().empty())
Bases.push_back(BaseDecl);
}
}
}
}
// Add the associated classes and namespaces for
// argument-dependent lookup with an argument of type T
// (C++ [basic.lookup.koenig]p2).
static void
addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
// C++ [basic.lookup.koenig]p2:
//
// For each argument type T in the function call, there is a set
// of zero or more associated namespaces and a set of zero or more
// associated classes to be considered. The sets of namespaces and
// classes is determined entirely by the types of the function
// arguments (and the namespace of any template template
// argument). Typedef names and using-declarations used to specify
// the types do not contribute to this set. The sets of namespaces
// and classes are determined in the following way:
SmallVector<const Type *, 16> Queue;
const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
while (true) {
switch (T->getTypeClass()) {
#define TYPE(Class, Base)
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
#define ABSTRACT_TYPE(Class, Base)
#include "clang/AST/TypeNodes.inc"
// T is canonical. We can also ignore dependent types because
// we don't need to do ADL at the definition point, but if we
// wanted to implement template export (or if we find some other
// use for associated classes and namespaces...) this would be
// wrong.
break;
// -- If T is a pointer to U or an array of U, its associated
// namespaces and classes are those associated with U.
case Type::Pointer:
T = cast<PointerType>(T)->getPointeeType().getTypePtr();
continue;
case Type::ConstantArray:
case Type::IncompleteArray:
case Type::VariableArray:
T = cast<ArrayType>(T)->getElementType().getTypePtr();
continue;
// -- If T is a fundamental type, its associated sets of
// namespaces and classes are both empty.
case Type::Builtin:
break;
// -- If T is a class type (including unions), its associated
// classes are: the class itself; the class of which it is
// a member, if any; and its direct and indirect base classes.
// Its associated namespaces are the innermost enclosing
// namespaces of its associated classes.
case Type::Record: {
// FIXME: This should use the original decl.
CXXRecordDecl *Class =
cast<CXXRecordDecl>(cast<RecordType>(T)->getOriginalDecl())
->getDefinitionOrSelf();
addAssociatedClassesAndNamespaces(Result, Class);
break;
}
// -- If T is an enumeration type, its associated namespace
// is the innermost enclosing namespace of its declaration.
// If it is a class member, its associated class is the
// member’s class; else it has no associated class.
case Type::Enum: {
// FIXME: This should use the original decl.
auto *Enum = T->castAsEnumDecl();
DeclContext *Ctx = Enum->getDeclContext();
if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
Result.Classes.insert(EnclosingClass);
// Add the associated namespace for this enumeration.
CollectEnclosingNamespace(Result.Namespaces, Ctx);
break;
}
// -- If T is a function type, its associated namespaces and
// classes are those associated with the function parameter
// types and those associated with the return type.
case Type::FunctionProto: {
const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
for (const auto &Arg : Proto->param_types())
Queue.push_back(Arg.getTypePtr());
// fallthrough
[[fallthrough]];
}
case Type::FunctionNoProto: {
const FunctionType *FnType = cast<FunctionType>(T);
T = FnType->getReturnType().getTypePtr();
continue;
}
// -- If T is a pointer to a member function of a class X, its
// associated namespaces and classes are those associated
// with the function parameter types and return type,
// together with those associated with X.
//
// -- If T is a pointer to a data member of class X, its
// associated namespaces and classes are those associated
// with the member type together with those associated with
// X.
case Type::MemberPointer: {
const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
if (CXXRecordDecl *Class = MemberPtr->getMostRecentCXXRecordDecl())
addAssociatedClassesAndNamespaces(Result, Class);
T = MemberPtr->getPointeeType().getTypePtr();
continue;
}
// As an extension, treat this like a normal pointer.
case Type::BlockPointer:
T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
continue;
// References aren't covered by the standard, but that's such an
// obvious defect that we cover them anyway.
case Type::LValueReference:
case Type::RValueReference:
T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
continue;
// These are fundamental types.
case Type::Vector:
case Type::ExtVector:
case Type::ConstantMatrix:
case Type::Complex:
case Type::BitInt:
break;
// Non-deduced auto types only get here for error cases.
case Type::Auto:
case Type::DeducedTemplateSpecialization:
break;
// If T is an Objective-C object or interface type, or a pointer to an
// object or interface type, the associated namespace is the global
// namespace.
case Type::ObjCObject:
case Type::ObjCInterface:
case Type::ObjCObjectPointer:
Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
break;
// Atomic types are just wrappers; use the associations of the
// contained type.
case Type::Atomic:
T = cast<AtomicType>(T)->getValueType().getTypePtr();
continue;
case Type::Pipe:
T = cast<PipeType>(T)->getElementType().getTypePtr();
continue;
// Array parameter types are treated as fundamental types.
case Type::ArrayParameter:
break;
case Type::HLSLAttributedResource:
T = cast<HLSLAttributedResourceType>(T)->getWrappedType().getTypePtr();
break;
// Inline SPIR-V types are treated as fundamental types.
case Type::HLSLInlineSpirv:
break;
}
if (Queue.empty())
break;
T = Queue.pop_back_val();
}
}
void Sema::FindAssociatedClassesAndNamespaces(
SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
AssociatedNamespaceSet &AssociatedNamespaces,
AssociatedClassSet &AssociatedClasses) {
AssociatedNamespaces.clear();
AssociatedClasses.clear();
AssociatedLookup Result(*this, InstantiationLoc,
AssociatedNamespaces, AssociatedClasses);
// C++ [basic.lookup.koenig]p2:
// For each argument type T in the function call, there is a set
// of zero or more associated namespaces and a set of zero or more
// associated classes to be considered. The sets of namespaces and
// classes is determined entirely by the types of the function
// arguments (and the namespace of any template template
// argument).
for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
Expr *Arg = Args[ArgIdx];
if (Arg->getType() != Context.OverloadTy) {
addAssociatedClassesAndNamespaces(Result, Arg->getType());
continue;
}
// [...] In addition, if the argument is the name or address of a
// set of overloaded functions and/or function templates, its
// associated classes and namespaces are the union of those
// associated with each of the members of the set: the namespace
// in which the function or function template is defined and the
// classes and namespaces associated with its (non-dependent)
// parameter types and return type.
OverloadExpr *OE = OverloadExpr::find(Arg).Expression;
for (const NamedDecl *D : OE->decls()) {
// Look through any using declarations to find the underlying function.
const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
// Add the classes and namespaces associated with the parameter
// types and return type of this function.
addAssociatedClassesAndNamespaces(Result, FDecl->getType());
}
}
}
NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
SourceLocation Loc,
LookupNameKind NameKind,
RedeclarationKind Redecl) {
LookupResult R(*this, Name, Loc, NameKind, Redecl);
LookupName(R, S);
return R.getAsSingle<NamedDecl>();
}
void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
UnresolvedSetImpl &Functions) {
// C++ [over.match.oper]p3:
// -- The set of non-member candidates is the result of the
// unqualified lookup of operator@ in the context of the
// expression according to the usual rules for name lookup in
// unqualified function calls (3.4.2) except that all member
// functions are ignored.
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
LookupName(Operators, S);
assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
Functions.append(Operators.begin(), Operators.end());
}
Sema::SpecialMemberOverloadResult
Sema::LookupSpecialMember(CXXRecordDecl *RD, CXXSpecialMemberKind SM,
bool ConstArg, bool VolatileArg, bool RValueThis,
bool ConstThis, bool VolatileThis) {
assert(CanDeclareSpecialMemberFunction(RD) &&
"doing special member lookup into record that isn't fully complete");
RD = RD->getDefinition();
if (RValueThis || ConstThis || VolatileThis)
assert((SM == CXXSpecialMemberKind::CopyAssignment ||
SM == CXXSpecialMemberKind::MoveAssignment) &&
"constructors and destructors always have unqualified lvalue this");
if (ConstArg || VolatileArg)
assert((SM != CXXSpecialMemberKind::DefaultConstructor &&
SM != CXXSpecialMemberKind::Destructor) &&
"parameter-less special members can't have qualified arguments");
// FIXME: Get the caller to pass in a location for the lookup.
SourceLocation LookupLoc = RD->getLocation();
llvm::FoldingSetNodeID ID;
ID.AddPointer(RD);
ID.AddInteger(llvm::to_underlying(SM));
ID.AddInteger(ConstArg);
ID.AddInteger(VolatileArg);
ID.AddInteger(RValueThis);
ID.AddInteger(ConstThis);
ID.AddInteger(VolatileThis);
void *InsertPoint;
SpecialMemberOverloadResultEntry *Result =
SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
// This was already cached
if (Result)
return *Result;
Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
Result = new (Result) SpecialMemberOverloadResultEntry(ID);
SpecialMemberCache.InsertNode(Result, InsertPoint);
if (SM == CXXSpecialMemberKind::Destructor) {
if (RD->needsImplicitDestructor()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitDestructor(RD);
});
}
CXXDestructorDecl *DD = RD->getDestructor();
Result->setMethod(DD);
Result->setKind(DD && !DD->isDeleted()
? SpecialMemberOverloadResult::Success
: SpecialMemberOverloadResult::NoMemberOrDeleted);
return *Result;
}
// Prepare for overload resolution. Here we construct a synthetic argument
// if necessary and make sure that implicit functions are declared.
CanQualType CanTy = Context.getCanonicalTagType(RD);
DeclarationName Name;
Expr *Arg = nullptr;
unsigned NumArgs;
QualType ArgType = CanTy;
ExprValueKind VK = VK_LValue;
if (SM == CXXSpecialMemberKind::DefaultConstructor) {
Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
NumArgs = 0;
if (RD->needsImplicitDefaultConstructor()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitDefaultConstructor(RD);
});
}
} else {
if (SM == CXXSpecialMemberKind::CopyConstructor ||
SM == CXXSpecialMemberKind::MoveConstructor) {
Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
if (RD->needsImplicitCopyConstructor()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitCopyConstructor(RD);
});
}
if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitMoveConstructor(RD);
});
}
} else {
Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
if (RD->needsImplicitCopyAssignment()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitCopyAssignment(RD);
});
}
if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) {
runWithSufficientStackSpace(RD->getLocation(), [&] {
DeclareImplicitMoveAssignment(RD);
});
}
}
if (ConstArg)
ArgType.addConst();
if (VolatileArg)
ArgType.addVolatile();
// This isn't /really/ specified by the standard, but it's implied
// we should be working from a PRValue in the case of move to ensure
// that we prefer to bind to rvalue references, and an LValue in the
// case of copy to ensure we don't bind to rvalue references.
// Possibly an XValue is actually correct in the case of move, but
// there is no semantic difference for class types in this restricted
// case.
if (SM == CXXSpecialMemberKind::CopyConstructor ||
SM == CXXSpecialMemberKind::CopyAssignment)
VK = VK_LValue;
else
VK = VK_PRValue;
}
OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
if (SM != CXXSpecialMemberKind::DefaultConstructor) {
NumArgs = 1;
Arg = &FakeArg;
}
// Create the object argument
QualType ThisTy = CanTy;
if (ConstThis)
ThisTy.addConst();
if (VolatileThis)
ThisTy.addVolatile();
Expr::Classification Classification =
OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue)
.Classify(Context);
// Now we perform lookup on the name we computed earlier and do overload
// resolution. Lookup is only performed directly into the class since there
// will always be a (possibly implicit) declaration to shadow any others.
OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
DeclContext::lookup_result R = RD->lookup(Name);
if (R.empty()) {
// We might have no default constructor because we have a lambda's closure
// type, rather than because there's some other declared constructor.
// Every class has a copy/move constructor, copy/move assignment, and
// destructor.
assert(SM == CXXSpecialMemberKind::DefaultConstructor &&
"lookup for a constructor or assignment operator was empty");
Result->setMethod(nullptr);
Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
return *Result;
}
// Copy the candidates as our processing of them may load new declarations
// from an external source and invalidate lookup_result.
SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
for (NamedDecl *CandDecl : Candidates) {
if (CandDecl->isInvalidDecl())
continue;
DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
auto CtorInfo = getConstructorInfo(Cand);
if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
if (SM == CXXSpecialMemberKind::CopyAssignment ||
SM == CXXSpecialMemberKind::MoveAssignment)
AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
llvm::ArrayRef(&Arg, NumArgs), OCS, true);
else if (CtorInfo)
AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
llvm::ArrayRef(&Arg, NumArgs), OCS,
/*SuppressUserConversions*/ true);
else
AddOverloadCandidate(M, Cand, llvm::ArrayRef(&Arg, NumArgs), OCS,
/*SuppressUserConversions*/ true);
} else if (FunctionTemplateDecl *Tmpl =
dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
if (SM == CXXSpecialMemberKind::CopyAssignment ||
SM == CXXSpecialMemberKind::MoveAssignment)
AddMethodTemplateCandidate(Tmpl, Cand, RD, nullptr, ThisTy,
Classification,
llvm::ArrayRef(&Arg, NumArgs), OCS, true);
else if (CtorInfo)
AddTemplateOverloadCandidate(CtorInfo.ConstructorTmpl,
CtorInfo.FoundDecl, nullptr,
llvm::ArrayRef(&Arg, NumArgs), OCS, true);
else
AddTemplateOverloadCandidate(Tmpl, Cand, nullptr,
llvm::ArrayRef(&Arg, NumArgs), OCS, true);
} else {
assert(isa<UsingDecl>(Cand.getDecl()) &&
"illegal Kind of operator = Decl");
}
}
OverloadCandidateSet::iterator Best;
switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
case OR_Success:
Result->setMethod(cast<CXXMethodDecl>(Best->Function));
Result->setKind(SpecialMemberOverloadResult::Success);
break;
case OR_Deleted:
Result->setMethod(cast<CXXMethodDecl>(Best->Function));
Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
break;
case OR_Ambiguous:
Result->setMethod(nullptr);
Result->setKind(SpecialMemberOverloadResult::Ambiguous);
break;
case OR_No_Viable_Function:
Result->setMethod(nullptr);
Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
break;
}
return *Result;
}
CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
SpecialMemberOverloadResult Result =
LookupSpecialMember(Class, CXXSpecialMemberKind::DefaultConstructor,
false, false, false, false, false);
return cast_or_null<CXXConstructorDecl>(Result.getMethod());
}
CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
unsigned Quals) {
assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy ctor arg");
SpecialMemberOverloadResult Result = LookupSpecialMember(
Class, CXXSpecialMemberKind::CopyConstructor, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, false, false, false);
return cast_or_null<CXXConstructorDecl>(Result.getMethod());
}
CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
unsigned Quals) {
SpecialMemberOverloadResult Result = LookupSpecialMember(
Class, CXXSpecialMemberKind::MoveConstructor, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, false, false, false);
return cast_or_null<CXXConstructorDecl>(Result.getMethod());
}
DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
// If the implicit constructors have not yet been declared, do so now.
if (CanDeclareSpecialMemberFunction(Class)) {
runWithSufficientStackSpace(Class->getLocation(), [&] {
if (Class->needsImplicitDefaultConstructor())
DeclareImplicitDefaultConstructor(Class);
if (Class->needsImplicitCopyConstructor())
DeclareImplicitCopyConstructor(Class);
if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
DeclareImplicitMoveConstructor(Class);
});
}
CanQualType T = Context.getCanonicalTagType(Class);
DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
return Class->lookup(Name);
}
CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
unsigned Quals, bool RValueThis,
unsigned ThisQuals) {
assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment arg");
assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment this");
SpecialMemberOverloadResult Result = LookupSpecialMember(
Class, CXXSpecialMemberKind::CopyAssignment, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, RValueThis, ThisQuals & Qualifiers::Const,
ThisQuals & Qualifiers::Volatile);
return Result.getMethod();
}
CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
unsigned Quals,
bool RValueThis,
unsigned ThisQuals) {
assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
"non-const, non-volatile qualifiers for copy assignment this");
SpecialMemberOverloadResult Result = LookupSpecialMember(
Class, CXXSpecialMemberKind::MoveAssignment, Quals & Qualifiers::Const,
Quals & Qualifiers::Volatile, RValueThis, ThisQuals & Qualifiers::Const,
ThisQuals & Qualifiers::Volatile);
return Result.getMethod();
}
CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
return cast_or_null<CXXDestructorDecl>(
LookupSpecialMember(Class, CXXSpecialMemberKind::Destructor, false, false,
false, false, false)
.getMethod());
}
Sema::LiteralOperatorLookupResult
Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
ArrayRef<QualType> ArgTys, bool AllowRaw,
bool AllowTemplate, bool AllowStringTemplatePack,
bool DiagnoseMissing, StringLiteral *StringLit) {
LookupName(R, S);
assert(R.getResultKind() != LookupResultKind::Ambiguous &&
"literal operator lookup can't be ambiguous");
// Filter the lookup results appropriately.
LookupResult::Filter F = R.makeFilter();
bool AllowCooked = true;
bool FoundRaw = false;
bool FoundTemplate = false;
bool FoundStringTemplatePack = false;
bool FoundCooked = false;
while (F.hasNext()) {
Decl *D = F.next();
if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
D = USD->getTargetDecl();
// If the declaration we found is invalid, skip it.
if (D->isInvalidDecl()) {
F.erase();
continue;
}
bool IsRaw = false;
bool IsTemplate = false;
bool IsStringTemplatePack = false;
bool IsCooked = false;
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (FD->getNumParams() == 1 &&
FD->getParamDecl(0)->getType()->getAs<PointerType>())
IsRaw = true;
else if (FD->getNumParams() == ArgTys.size()) {
IsCooked = true;
for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
IsCooked = false;
break;
}
}
}
}
if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
TemplateParameterList *Params = FD->getTemplateParameters();
if (Params->size() == 1) {
IsTemplate = true;
if (!Params->getParam(0)->isTemplateParameterPack() && !StringLit) {
// Implied but not stated: user-defined integer and floating literals
// only ever use numeric literal operator templates, not templates
// taking a parameter of class type.
F.erase();
continue;
}
// A string literal template is only considered if the string literal
// is a well-formed template argument for the template parameter.
if (StringLit) {
SFINAETrap Trap(*this);
CheckTemplateArgumentInfo CTAI;
TemplateArgumentLoc Arg(
TemplateArgument(StringLit, /*IsCanonical=*/false), StringLit);
if (CheckTemplateArgument(
Params->getParam(0), Arg, FD, R.getNameLoc(), R.getNameLoc(),
/*ArgumentPackIndex=*/0, CTAI, CTAK_Specified) ||
Trap.hasErrorOccurred())
IsTemplate = false;
}
} else {
IsStringTemplatePack = true;
}
}
if (AllowTemplate && StringLit && IsTemplate) {
FoundTemplate = true;
AllowRaw = false;
AllowCooked = false;
AllowStringTemplatePack = false;
if (FoundRaw || FoundCooked || FoundStringTemplatePack) {
F.restart();
FoundRaw = FoundCooked = FoundStringTemplatePack = false;
}
} else if (AllowCooked && IsCooked) {
FoundCooked = true;
AllowRaw = false;
AllowTemplate = StringLit;
AllowStringTemplatePack = false;
if (FoundRaw || FoundTemplate || FoundStringTemplatePack) {
// Go through again and remove the raw and template decls we've
// already found.
F.restart();
FoundRaw = FoundTemplate = FoundStringTemplatePack = false;
}
} else if (AllowRaw && IsRaw) {
FoundRaw = true;
} else if (AllowTemplate && IsTemplate) {
FoundTemplate = true;
} else if (AllowStringTemplatePack && IsStringTemplatePack) {
FoundStringTemplatePack = true;
} else {
F.erase();
}
}
F.done();
// Per C++20 [lex.ext]p5, we prefer the template form over the non-template
// form for string literal operator templates.
if (StringLit && FoundTemplate)
return LOLR_Template;
// C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
// parameter type, that is used in preference to a raw literal operator
// or literal operator template.
if (FoundCooked)
return LOLR_Cooked;
// C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
// operator template, but not both.
if (FoundRaw && FoundTemplate) {
Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
for (const NamedDecl *D : R)
NoteOverloadCandidate(D, D->getUnderlyingDecl()->getAsFunction());
return LOLR_Error;
}
if (FoundRaw)
return LOLR_Raw;
if (FoundTemplate)
return LOLR_Template;
if (FoundStringTemplatePack)
return LOLR_StringTemplatePack;
// Didn't find anything we could use.
if (DiagnoseMissing) {
Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
<< R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
<< (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
<< (AllowTemplate || AllowStringTemplatePack);
return LOLR_Error;
}
return LOLR_ErrorNoDiagnostic;
}
void ADLResult::insert(NamedDecl *New) {
NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
// If we haven't yet seen a decl for this key, or the last decl
// was exactly this one, we're done.
if (Old == nullptr || Old == New) {
Old = New;
return;
}
// Otherwise, decide which is a more recent redeclaration.
FunctionDecl *OldFD = Old->getAsFunction();
FunctionDecl *NewFD = New->getAsFunction();
FunctionDecl *Cursor = NewFD;
while (true) {
Cursor = Cursor->getPreviousDecl();
// If we got to the end without finding OldFD, OldFD is the newer
// declaration; leave things as they are.
if (!Cursor) return;
// If we do find OldFD, then NewFD is newer.
if (Cursor == OldFD) break;
// Otherwise, keep looking.
}
Old = New;
}
void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
ArrayRef<Expr *> Args, ADLResult &Result) {
// Find all of the associated namespaces and classes based on the
// arguments we have.
AssociatedNamespaceSet AssociatedNamespaces;
AssociatedClassSet AssociatedClasses;
FindAssociatedClassesAndNamespaces(Loc, Args,
AssociatedNamespaces,
AssociatedClasses);
// C++ [basic.lookup.argdep]p3:
// Let X be the lookup set produced by unqualified lookup (3.4.1)
// and let Y be the lookup set produced by argument dependent
// lookup (defined as follows). If X contains [...] then Y is
// empty. Otherwise Y is the set of declarations found in the
// namespaces associated with the argument types as described
// below. The set of declarations found by the lookup of the name
// is the union of X and Y.
//
// Here, we compute Y and add its members to the overloaded
// candidate set.
for (auto *NS : AssociatedNamespaces) {
// When considering an associated namespace, the lookup is the
// same as the lookup performed when the associated namespace is
// used as a qualifier (3.4.3.2) except that:
//
// -- Any using-directives in the associated namespace are
// ignored.
//
// -- Any namespace-scope friend functions declared in
// associated classes are visible within their respective
// namespaces even if they are not visible during an ordinary
// lookup (11.4).
//
// C++20 [basic.lookup.argdep] p4.3
// -- are exported, are attached to a named module M, do not appear
// in the translation unit containing the point of the lookup, and
// have the same innermost enclosing non-inline namespace scope as
// a declaration of an associated entity attached to M.
DeclContext::lookup_result R = NS->lookup(Name);
for (auto *D : R) {
auto *Underlying = D;
if (auto *USD = dyn_cast<UsingShadowDecl>(D))
Underlying = USD->getTargetDecl();
if (!isa<FunctionDecl>(Underlying) &&
!isa<FunctionTemplateDecl>(Underlying))
continue;
// The declaration is visible to argument-dependent lookup if either
// it's ordinarily visible or declared as a friend in an associated
// class.
bool Visible = false;
for (D = D->getMostRecentDecl(); D;
D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) {
if (isVisible(D)) {
Visible = true;
break;
}
if (!getLangOpts().CPlusPlusModules)
continue;
if (D->isInExportDeclContext()) {
Module *FM = D->getOwningModule();
// C++20 [basic.lookup.argdep] p4.3 .. are exported ...
// exports are only valid in module purview and outside of any
// PMF (although a PMF should not even be present in a module
// with an import).
assert(FM &&
(FM->isNamedModule() || FM->isImplicitGlobalModule()) &&
!FM->isPrivateModule() && "bad export context");
// .. are attached to a named module M, do not appear in the
// translation unit containing the point of the lookup..
if (D->isInAnotherModuleUnit() &&
llvm::any_of(AssociatedClasses, [&](auto *E) {
// ... and have the same innermost enclosing non-inline
// namespace scope as a declaration of an associated entity
// attached to M
if (E->getOwningModule() != FM)
return false;
// TODO: maybe this could be cached when generating the
// associated namespaces / entities.
DeclContext *Ctx = E->getDeclContext();
while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
Ctx = Ctx->getParent();
return Ctx == NS;
})) {
Visible = true;
break;
}
}
} else if (D->getFriendObjectKind()) {
auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
// [basic.lookup.argdep]p4:
// Argument-dependent lookup finds all declarations of functions and
// function templates that
// - ...
// - are declared as a friend ([class.friend]) of any class with a
// reachable definition in the set of associated entities,
//
// FIXME: If there's a merged definition of D that is reachable, then
// the friend declaration should be considered.
if (AssociatedClasses.count(RD) && isReachable(D)) {
Visible = true;
break;
}
}
}
// FIXME: Preserve D as the FoundDecl.
if (Visible)
Result.insert(Underlying);
}
}
}
//----------------------------------------------------------------------------
// Search for all visible declarations.
//----------------------------------------------------------------------------
VisibleDeclConsumer::~VisibleDeclConsumer() { }
bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
namespace {
class ShadowContextRAII;
class VisibleDeclsRecord {
public:
/// An entry in the shadow map, which is optimized to store a
/// single declaration (the common case) but can also store a list
/// of declarations.
typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
private:
/// A mapping from declaration names to the declarations that have
/// this name within a particular scope.
typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
/// A list of shadow maps, which is used to model name hiding.
std::list<ShadowMap> ShadowMaps;
/// The declaration contexts we have already visited.
llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
friend class ShadowContextRAII;
public:
/// Determine whether we have already visited this context
/// (and, if not, note that we are going to visit that context now).
bool visitedContext(DeclContext *Ctx) {
return !VisitedContexts.insert(Ctx).second;
}
bool alreadyVisitedContext(DeclContext *Ctx) {
return VisitedContexts.count(Ctx);
}
/// Determine whether the given declaration is hidden in the
/// current scope.
///
/// \returns the declaration that hides the given declaration, or
/// NULL if no such declaration exists.
NamedDecl *checkHidden(NamedDecl *ND);
/// Add a declaration to the current shadow map.
void add(NamedDecl *ND) {
ShadowMaps.back()[ND->getDeclName()].push_back(ND);
}
};
/// RAII object that records when we've entered a shadow context.
class ShadowContextRAII {
VisibleDeclsRecord &Visible;
typedef VisibleDeclsRecord::ShadowMap ShadowMap;
public:
ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
Visible.ShadowMaps.emplace_back();
}
~ShadowContextRAII() {
Visible.ShadowMaps.pop_back();
}
};
} // end anonymous namespace
NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
unsigned IDNS = ND->getIdentifierNamespace();
std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
SM != SMEnd; ++SM) {
ShadowMap::iterator Pos = SM->find(ND->getDeclName());
if (Pos == SM->end())
continue;
for (auto *D : Pos->second) {
// A tag declaration does not hide a non-tag declaration.
if (D->hasTagIdentifierNamespace() &&
(IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
Decl::IDNS_ObjCProtocol)))
continue;
// Protocols are in distinct namespaces from everything else.
if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
|| (IDNS & Decl::IDNS_ObjCProtocol)) &&
D->getIdentifierNamespace() != IDNS)
continue;
// Functions and function templates in the same scope overload
// rather than hide. FIXME: Look for hiding based on function
// signatures!
if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
SM == ShadowMaps.rbegin())
continue;
// A shadow declaration that's created by a resolved using declaration
// is not hidden by the same using declaration.
if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
cast<UsingShadowDecl>(ND)->getIntroducer() == D)
continue;
// We've found a declaration that hides this one.
return D;
}
}
return nullptr;
}
namespace {
class LookupVisibleHelper {
public:
LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
bool LoadExternal)
: Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
LoadExternal(LoadExternal) {}
void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind,
bool IncludeGlobalScope) {
// Determine the set of using directives available during
// unqualified name lookup.
Scope *Initial = S;
UnqualUsingDirectiveSet UDirs(SemaRef);
if (SemaRef.getLangOpts().CPlusPlus) {
// Find the first namespace or translation-unit scope.
while (S && !isNamespaceOrTranslationUnitScope(S))
S = S->getParent();
UDirs.visitScopeChain(Initial, S);
}
UDirs.done();
// Look for visible declarations.
LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
Result.setAllowHidden(Consumer.includeHiddenDecls());
if (!IncludeGlobalScope)
Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
ShadowContextRAII Shadow(Visited);
lookupInScope(Initial, Result, UDirs);
}
void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
Result.setAllowHidden(Consumer.includeHiddenDecls());
if (!IncludeGlobalScope)
Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl());
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
/*InBaseClass=*/false);
}
private:
void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
bool QualifiedNameLookup, bool InBaseClass) {
if (!Ctx)
return;
// Make sure we don't visit the same context twice.
if (Visited.visitedContext(Ctx->getPrimaryContext()))
return;
Consumer.EnteredContext(Ctx);
// Outside C++, lookup results for the TU live on identifiers.
if (isa<TranslationUnitDecl>(Ctx) &&
!Result.getSema().getLangOpts().CPlusPlus) {
auto &S = Result.getSema();
auto &Idents = S.Context.Idents;
// Ensure all external identifiers are in the identifier table.
if (LoadExternal)
if (IdentifierInfoLookup *External =
Idents.getExternalIdentifierLookup()) {
std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
for (StringRef Name = Iter->Next(); !Name.empty();
Name = Iter->Next())
Idents.get(Name);
}
// Walk all lookup results in the TU for each identifier.
for (const auto &Ident : Idents) {
for (auto I = S.IdResolver.begin(Ident.getValue()),
E = S.IdResolver.end();
I != E; ++I) {
if (S.IdResolver.isDeclInScope(*I, Ctx)) {
if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
Visited.add(ND);
}
}
}
}
return;
}
if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
Result.getSema().ForceDeclarationOfImplicitMembers(Class);
llvm::SmallVector<NamedDecl *, 4> DeclsToVisit;
// We sometimes skip loading namespace-level results (they tend to be huge).
bool Load = LoadExternal ||
!(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
// Enumerate all of the results in this context.
for (DeclContextLookupResult R :
Load ? Ctx->lookups()
: Ctx->noload_lookups(/*PreserveInternalState=*/false))
for (auto *D : R)
// Rather than visit immediately, we put ND into a vector and visit
// all decls, in order, outside of this loop. The reason is that
// Consumer.FoundDecl() and LookupResult::getAcceptableDecl(D)
// may invalidate the iterators used in the two
// loops above.
DeclsToVisit.push_back(D);
for (auto *D : DeclsToVisit)
if (auto *ND = Result.getAcceptableDecl(D)) {
Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
Visited.add(ND);
}
DeclsToVisit.clear();
// Traverse using directives for qualified name lookup.
if (QualifiedNameLookup) {
ShadowContextRAII Shadow(Visited);
for (auto *I : Ctx->using_directives()) {
if (!Result.getSema().isVisible(I))
continue;
lookupInDeclContext(I->getNominatedNamespace(), Result,
QualifiedNameLookup, InBaseClass);
}
}
// Traverse the contexts of inherited C++ classes.
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
if (!Record->hasDefinition())
return;
for (const auto &B : Record->bases()) {
QualType BaseType = B.getType();
RecordDecl *RD;
if (BaseType->isDependentType()) {
if (!IncludeDependentBases) {
// Don't look into dependent bases, because name lookup can't look
// there anyway.
continue;
}
const auto *TST = BaseType->getAs<TemplateSpecializationType>();
if (!TST)
continue;
TemplateName TN = TST->getTemplateName();
const auto *TD =
dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
if (!TD)
continue;
RD = TD->getTemplatedDecl();
} else {
RD = BaseType->getAsCXXRecordDecl();
if (!RD)
continue;
}
// FIXME: It would be nice to be able to determine whether referencing
// a particular member would be ambiguous. For example, given
//
// struct A { int member; };
// struct B { int member; };
// struct C : A, B { };
//
// void f(C *c) { c->### }
//
// accessing 'member' would result in an ambiguity. However, we
// could be smart enough to qualify the member with the base
// class, e.g.,
//
// c->B::member
//
// or
//
// c->A::member
// Find results in this base class (and its bases).
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(RD, Result, QualifiedNameLookup,
/*InBaseClass=*/true);
}
}
// Traverse the contexts of Objective-C classes.
if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
// Traverse categories.
for (auto *Cat : IFace->visible_categories()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(Cat, Result, QualifiedNameLookup,
/*InBaseClass=*/false);
}
// Traverse protocols.
for (auto *I : IFace->all_referenced_protocols()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(I, Result, QualifiedNameLookup,
/*InBaseClass=*/false);
}
// Traverse the superclass.
if (IFace->getSuperClass()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup,
/*InBaseClass=*/true);
}
// If there is an implementation, traverse it. We do this to find
// synthesized ivars.
if (IFace->getImplementation()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(IFace->getImplementation(), Result,
QualifiedNameLookup, InBaseClass);
}
} else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
for (auto *I : Protocol->protocols()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(I, Result, QualifiedNameLookup,
/*InBaseClass=*/false);
}
} else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
for (auto *I : Category->protocols()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(I, Result, QualifiedNameLookup,
/*InBaseClass=*/false);
}
// If there is an implementation, traverse it.
if (Category->getImplementation()) {
ShadowContextRAII Shadow(Visited);
lookupInDeclContext(Category->getImplementation(), Result,
QualifiedNameLookup, /*InBaseClass=*/true);
}
}
}
void lookupInScope(Scope *S, LookupResult &Result,
UnqualUsingDirectiveSet &UDirs) {
// No clients run in this mode and it's not supported. Please add tests and
// remove the assertion if you start relying on it.
assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
if (!S)
return;
if (!S->getEntity() ||
(!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) ||
(S->getEntity())->isFunctionOrMethod()) {
FindLocalExternScope FindLocals(Result);
// Walk through the declarations in this Scope. The consumer might add new
// decls to the scope as part of deserialization, so make a copy first.
SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
for (Decl *D : ScopeDecls) {
if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
if ((ND = Result.getAcceptableDecl(ND))) {
Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
Visited.add(ND);
}
}
}
DeclContext *Entity = S->getLookupEntity();
if (Entity) {
// Look into this scope's declaration context, along with any of its
// parent lookup contexts (e.g., enclosing classes), up to the point
// where we hit the context stored in the next outer scope.
DeclContext *OuterCtx = findOuterContext(S);
for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
Ctx = Ctx->getLookupParent()) {
if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
if (Method->isInstanceMethod()) {
// For instance methods, look for ivars in the method's interface.
LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
Result.getNameLoc(),
Sema::LookupMemberName);
if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
lookupInDeclContext(IFace, IvarResult,
/*QualifiedNameLookup=*/false,
/*InBaseClass=*/false);
}
}
// We've already performed all of the name lookup that we need
// to for Objective-C methods; the next context will be the
// outer scope.
break;
}
if (Ctx->isFunctionOrMethod())
continue;
lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
/*InBaseClass=*/false);
}
} else if (!S->getParent()) {
// Look into the translation unit scope. We walk through the translation
// unit's declaration context, because the Scope itself won't have all of
// the declarations if we loaded a precompiled header.
// FIXME: We would like the translation unit's Scope object to point to
// the translation unit, so we don't need this special "if" branch.
// However, doing so would force the normal C++ name-lookup code to look
// into the translation unit decl when the IdentifierInfo chains would
// suffice. Once we fix that problem (which is part of a more general
// "don't look in DeclContexts unless we have to" optimization), we can
// eliminate this.
Entity = Result.getSema().Context.getTranslationUnitDecl();
lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false,
/*InBaseClass=*/false);
}
if (Entity) {
// Lookup visible declarations in any namespaces found by using
// directives.
for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
lookupInDeclContext(
const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
/*QualifiedNameLookup=*/false,
/*InBaseClass=*/false);
}
// Lookup names in the parent scope.
ShadowContextRAII Shadow(Visited);
lookupInScope(S->getParent(), Result, UDirs);
}
private:
VisibleDeclsRecord Visited;
VisibleDeclConsumer &Consumer;
bool IncludeDependentBases;
bool LoadExternal;
};
} // namespace
void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
VisibleDeclConsumer &Consumer,
bool IncludeGlobalScope, bool LoadExternal) {
LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
LoadExternal);
H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope);
}
void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
VisibleDeclConsumer &Consumer,
bool IncludeGlobalScope,
bool IncludeDependentBases, bool LoadExternal) {
LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope);
}
LabelDecl *Sema::LookupExistingLabel(IdentifierInfo *II, SourceLocation Loc) {
NamedDecl *Res = LookupSingleName(CurScope, II, Loc, LookupLabel,
RedeclarationKind::NotForRedeclaration);
// If we found a label, check to see if it is in the same context as us.
// When in a Block, we don't want to reuse a label in an enclosing function.
if (!Res || Res->getDeclContext() != CurContext)
return nullptr;
return cast<LabelDecl>(Res);
}
LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
SourceLocation GnuLabelLoc) {
if (GnuLabelLoc.isValid()) {
// Local label definitions always shadow existing labels.
auto *Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
Scope *S = CurScope;
PushOnScopeChains(Res, S, true);
return cast<LabelDecl>(Res);
}
// Not a GNU local label.
LabelDecl *Res = LookupExistingLabel(II, Loc);
if (!Res) {
// If not forward referenced or defined already, create the backing decl.
Res = LabelDecl::Create(Context, CurContext, Loc, II);
Scope *S = CurScope->getFnParent();
assert(S && "Not in a function?");
PushOnScopeChains(Res, S, true);
}
return Res;
}
//===----------------------------------------------------------------------===//
// Typo correction
//===----------------------------------------------------------------------===//
static bool isCandidateViable(CorrectionCandidateCallback &CCC,
TypoCorrection &Candidate) {
Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
}
static void LookupPotentialTypoResult(Sema &SemaRef,
LookupResult &Res,
IdentifierInfo *Name,
Scope *S, CXXScopeSpec *SS,
DeclContext *MemberContext,
bool EnteringContext,
bool isObjCIvarLookup,
bool FindHidden);
/// Check whether the declarations found for a typo correction are
/// visible. Set the correction's RequiresImport flag to true if none of the
/// declarations are visible, false otherwise.
static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
for (/**/; DI != DE; ++DI)
if (!LookupResult::isVisible(SemaRef, *DI))
break;
// No filtering needed if all decls are visible.
if (DI == DE) {
TC.setRequiresImport(false);
return;
}
llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
bool AnyVisibleDecls = !NewDecls.empty();
for (/**/; DI != DE; ++DI) {
if (LookupResult::isVisible(SemaRef, *DI)) {
if (!AnyVisibleDecls) {
// Found a visible decl, discard all hidden ones.
AnyVisibleDecls = true;
NewDecls.clear();
}
NewDecls.push_back(*DI);
} else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
NewDecls.push_back(*DI);
}
if (NewDecls.empty())
TC = TypoCorrection();
else {
TC.setCorrectionDecls(NewDecls);
TC.setRequiresImport(!AnyVisibleDecls);
}
}
// Fill the supplied vector with the IdentifierInfo pointers for each piece of
// the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
// fill the vector with the IdentifierInfo pointers for "foo" and "bar").
static void getNestedNameSpecifierIdentifiers(
NestedNameSpecifier NNS,
SmallVectorImpl<const IdentifierInfo *> &Identifiers) {
switch (NNS.getKind()) {
case NestedNameSpecifier::Kind::Null:
Identifiers.clear();
return;
case NestedNameSpecifier::Kind::Namespace: {
auto [Namespace, Prefix] = NNS.getAsNamespaceAndPrefix();
getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
if (const auto *NS = dyn_cast<NamespaceDecl>(Namespace);
NS && NS->isAnonymousNamespace())
return;
Identifiers.push_back(Namespace->getIdentifier());
return;
}
case NestedNameSpecifier::Kind::Type: {
for (const Type *T = NNS.getAsType(); /**/; /**/) {
switch (T->getTypeClass()) {
case Type::DependentName: {
auto *DT = cast<DependentNameType>(T);
getNestedNameSpecifierIdentifiers(DT->getQualifier(), Identifiers);
Identifiers.push_back(DT->getIdentifier());
return;
}
case Type::TemplateSpecialization: {
TemplateName Name =
cast<TemplateSpecializationType>(T)->getTemplateName();
if (const DependentTemplateName *DTN =
Name.getAsDependentTemplateName()) {
getNestedNameSpecifierIdentifiers(DTN->getQualifier(), Identifiers);
if (const auto *II = DTN->getName().getIdentifier())
Identifiers.push_back(II);
return;
}
if (const QualifiedTemplateName *QTN =
Name.getAsQualifiedTemplateName()) {
getNestedNameSpecifierIdentifiers(QTN->getQualifier(), Identifiers);
Name = QTN->getUnderlyingTemplate();
}
if (const auto *TD = Name.getAsTemplateDecl(/*IgnoreDeduced=*/true))
Identifiers.push_back(TD->getIdentifier());
return;
}
case Type::SubstTemplateTypeParm:
T = cast<SubstTemplateTypeParmType>(T)
->getReplacementType()
.getTypePtr();
continue;
case Type::TemplateTypeParm:
Identifiers.push_back(cast<TemplateTypeParmType>(T)->getIdentifier());
return;
case Type::Decltype:
return;
case Type::Enum:
case Type::Record:
case Type::InjectedClassName: {
auto *TT = cast<TagType>(T);
getNestedNameSpecifierIdentifiers(TT->getQualifier(), Identifiers);
Identifiers.push_back(TT->getOriginalDecl()->getIdentifier());
return;
}
case Type::Typedef: {
auto *TT = cast<TypedefType>(T);
getNestedNameSpecifierIdentifiers(TT->getQualifier(), Identifiers);
Identifiers.push_back(TT->getDecl()->getIdentifier());
return;
}
case Type::Using: {
auto *TT = cast<UsingType>(T);
getNestedNameSpecifierIdentifiers(TT->getQualifier(), Identifiers);
Identifiers.push_back(TT->getDecl()->getIdentifier());
return;
}
case Type::UnresolvedUsing: {
auto *TT = cast<UnresolvedUsingType>(T);
getNestedNameSpecifierIdentifiers(TT->getQualifier(), Identifiers);
Identifiers.push_back(TT->getDecl()->getIdentifier());
return;
}
default:
Identifiers.push_back(QualType(T, 0).getBaseTypeIdentifier());
return;
}
}
break;
}
case NestedNameSpecifier::Kind::Global:
case NestedNameSpecifier::Kind::MicrosoftSuper:
return;
}
}
void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
DeclContext *Ctx, bool InBaseClass) {
// Don't consider hidden names for typo correction.
if (Hiding)
return;
// Only consider entities with identifiers for names, ignoring
// special names (constructors, overloaded operators, selectors,
// etc.).
IdentifierInfo *Name = ND->getIdentifier();
if (!Name)
return;
// Only consider visible declarations and declarations from modules with
// names that exactly match.
if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
return;
FoundName(Name->getName());
}
void TypoCorrectionConsumer::FoundName(StringRef Name) {
// Compute the edit distance between the typo and the name of this
// entity, and add the identifier to the list of results.
addName(Name, nullptr);
}
void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
// Compute the edit distance between the typo and this keyword,
// and add the keyword to the list of results.
addName(Keyword, /*ND=*/nullptr, /*NNS=*/std::nullopt, /*isKeyword=*/true);
}
void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
NestedNameSpecifier NNS, bool isKeyword) {
// Use a simple length-based heuristic to determine the minimum possible
// edit distance. If the minimum isn't good enough, bail out early.
StringRef TypoStr = Typo->getName();
unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
if (MinED && TypoStr.size() / MinED < 3)
return;
// Compute an upper bound on the allowable edit distance, so that the
// edit-distance algorithm can short-circuit.
unsigned UpperBound = (TypoStr.size() + 2) / 3;
unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
if (ED > UpperBound) return;
TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
if (isKeyword) TC.makeKeyword();
TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
addCorrection(TC);
}
static const unsigned MaxTypoDistanceResultSets = 5;
void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
StringRef TypoStr = Typo->getName();
StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
// For very short typos, ignore potential corrections that have a different
// base identifier from the typo or which have a normalized edit distance
// longer than the typo itself.
if (TypoStr.size() < 3 &&
(Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
return;
// If the correction is resolved but is not viable, ignore it.
if (Correction.isResolved()) {
checkCorrectionVisibility(SemaRef, Correction);
if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
return;
}
TypoResultList &CList =
CorrectionResults[Correction.getEditDistance(false)][Name];
if (!CList.empty() && !CList.back().isResolved())
CList.pop_back();
if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
auto RI = llvm::find_if(CList, [NewND](const TypoCorrection &TypoCorr) {
return TypoCorr.getCorrectionDecl() == NewND;
});
if (RI != CList.end()) {
// The Correction refers to a decl already in the list. No insertion is
// necessary and all further cases will return.
auto IsDeprecated = [](Decl *D) {
while (D) {
if (D->isDeprecated())
return true;
D = llvm::dyn_cast_or_null<NamespaceDecl>(D->getDeclContext());
}
return false;
};
// Prefer non deprecated Corrections over deprecated and only then
// sort using an alphabetical order.
std::pair<bool, std::string> NewKey = {
IsDeprecated(Correction.getFoundDecl()),
Correction.getAsString(SemaRef.getLangOpts())};
std::pair<bool, std::string> PrevKey = {
IsDeprecated(RI->getFoundDecl()),
RI->getAsString(SemaRef.getLangOpts())};
if (NewKey < PrevKey)
*RI = Correction;
return;
}
}
if (CList.empty() || Correction.isResolved())
CList.push_back(Correction);
while (CorrectionResults.size() > MaxTypoDistanceResultSets)
CorrectionResults.erase(std::prev(CorrectionResults.end()));
}
void TypoCorrectionConsumer::addNamespaces(
const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
SearchNamespaces = true;
for (auto KNPair : KnownNamespaces)
Namespaces.addNameSpecifier(KNPair.first);
bool SSIsTemplate = false;
if (NestedNameSpecifier NNS = (SS ? SS->getScopeRep() : std::nullopt)) {
if (NNS.getKind() == NestedNameSpecifier::Kind::Type)
SSIsTemplate =
NNS.getAsType()->getTypeClass() == Type::TemplateSpecialization;
}
// Do not transform this into an iterator-based loop. The loop body can
// trigger the creation of further types (through lazy deserialization) and
// invalid iterators into this list.
auto &Types = SemaRef.getASTContext().getTypes();
for (unsigned I = 0; I != Types.size(); ++I) {
const auto *TI = Types[I];
if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
CD = CD->getCanonicalDecl();
if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
!CD->isUnion() && CD->getIdentifier() &&
(SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
(CD->isBeingDefined() || CD->isCompleteDefinition()))
Namespaces.addNameSpecifier(CD);
}
}
}
const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
if (++CurrentTCIndex < ValidatedCorrections.size())
return ValidatedCorrections[CurrentTCIndex];
CurrentTCIndex = ValidatedCorrections.size();
while (!CorrectionResults.empty()) {
auto DI = CorrectionResults.begin();
if (DI->second.empty()) {
CorrectionResults.erase(DI);
continue;
}
auto RI = DI->second.begin();
if (RI->second.empty()) {
DI->second.erase(RI);
performQualifiedLookups();
continue;
}
TypoCorrection TC = RI->second.pop_back_val();
if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
ValidatedCorrections.push_back(TC);
return ValidatedCorrections[CurrentTCIndex];
}
}
return ValidatedCorrections[0]; // The empty correction.
}
bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
DeclContext *TempMemberContext = MemberContext;
CXXScopeSpec *TempSS = SS.get();
retry_lookup:
LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
EnteringContext,
CorrectionValidator->IsObjCIvarLookup,
Name == Typo && !Candidate.WillReplaceSpecifier());
switch (Result.getResultKind()) {
case LookupResultKind::NotFound:
case LookupResultKind::NotFoundInCurrentInstantiation:
case LookupResultKind::FoundUnresolvedValue:
if (TempSS) {
// Immediately retry the lookup without the given CXXScopeSpec
TempSS = nullptr;
Candidate.WillReplaceSpecifier(true);
goto retry_lookup;
}
if (TempMemberContext) {
if (SS && !TempSS)
TempSS = SS.get();
TempMemberContext = nullptr;
goto retry_lookup;
}
if (SearchNamespaces)
QualifiedResults.push_back(Candidate);
break;
case LookupResultKind::Ambiguous:
// We don't deal with ambiguities.
break;
case LookupResultKind::Found:
case LookupResultKind::FoundOverloaded:
// Store all of the Decls for overloaded symbols
for (auto *TRD : Result)
Candidate.addCorrectionDecl(TRD);
checkCorrectionVisibility(SemaRef, Candidate);
if (!isCandidateViable(*CorrectionValidator, Candidate)) {
if (SearchNamespaces)
QualifiedResults.push_back(Candidate);
break;
}
Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
return true;
}
return false;
}
void TypoCorrectionConsumer::performQualifiedLookups() {
unsigned TypoLen = Typo->getName().size();
for (const TypoCorrection &QR : QualifiedResults) {
for (const auto &NSI : Namespaces) {
DeclContext *Ctx = NSI.DeclCtx;
CXXRecordDecl *NamingClass = NSI.NameSpecifier.getAsRecordDecl();
// If the current NestedNameSpecifier refers to a class and the
// current correction candidate is the name of that class, then skip
// it as it is unlikely a qualified version of the class' constructor
// is an appropriate correction.
if (NamingClass &&
NamingClass->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
continue;
TypoCorrection TC(QR);
TC.ClearCorrectionDecls();
TC.setCorrectionSpecifier(NSI.NameSpecifier);
TC.setQualifierDistance(NSI.EditDistance);
TC.setCallbackDistance(0); // Reset the callback distance
// If the current correction candidate and namespace combination are
// too far away from the original typo based on the normalized edit
// distance, then skip performing a qualified name lookup.
unsigned TmpED = TC.getEditDistance(true);
if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
TypoLen / TmpED < 3)
continue;
Result.clear();
Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
if (!SemaRef.LookupQualifiedName(Result, Ctx))
continue;
// Any corrections added below will be validated in subsequent
// iterations of the main while() loop over the Consumer's contents.
switch (Result.getResultKind()) {
case LookupResultKind::Found:
case LookupResultKind::FoundOverloaded: {
if (SS && SS->isValid()) {
std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
std::string OldQualified;
llvm::raw_string_ostream OldOStream(OldQualified);
SS->getScopeRep().print(OldOStream, SemaRef.getPrintingPolicy());
OldOStream << Typo->getName();
// If correction candidate would be an identical written qualified
// identifier, then the existing CXXScopeSpec probably included a
// typedef that didn't get accounted for properly.
if (OldOStream.str() == NewQualified)
break;
}
for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
TRD != TRDEnd; ++TRD) {
if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
NamingClass,
TRD.getPair()) == Sema::AR_accessible)
TC.addCorrectionDecl(*TRD);
}
if (TC.isResolved()) {
TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
addCorrection(TC);
}
break;
}
case LookupResultKind::NotFound:
case LookupResultKind::NotFoundInCurrentInstantiation:
case LookupResultKind::Ambiguous:
case LookupResultKind::FoundUnresolvedValue:
break;
}
}
}
QualifiedResults.clear();
}
TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
: Context(Context), CurContextChain(buildContextChain(CurContext)) {
if (NestedNameSpecifier NNS =
CurScopeSpec ? CurScopeSpec->getScopeRep() : std::nullopt) {
llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
NNS.print(SpecifierOStream, Context.getPrintingPolicy());
getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
}
// Build the list of identifiers that would be used for an absolute
// (from the global context) NestedNameSpecifier referring to the current
// context.
for (DeclContext *C : llvm::reverse(CurContextChain)) {
if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
CurContextIdentifiers.push_back(ND->getIdentifier());
}
// Add the global context as a NestedNameSpecifier
SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
NestedNameSpecifier::getGlobal(), 1};
DistanceMap[1].push_back(SI);
}
auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
DeclContext *Start) -> DeclContextList {
assert(Start && "Building a context chain from a null context");
DeclContextList Chain;
for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
DC = DC->getLookupParent()) {
NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
!(ND && ND->isAnonymousNamespace()))
Chain.push_back(DC->getPrimaryContext());
}
return Chain;
}
unsigned
TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
DeclContextList &DeclChain, NestedNameSpecifier &NNS) {
unsigned NumSpecifiers = 0;
for (DeclContext *C : llvm::reverse(DeclChain)) {
if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
NNS = NestedNameSpecifier(Context, ND, NNS);
++NumSpecifiers;
} else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
QualType T = Context.getTagType(ElaboratedTypeKeyword::None, NNS, RD,
/*OwnsTag=*/false);
NNS = NestedNameSpecifier(T.getTypePtr());
++NumSpecifiers;
}
}
return NumSpecifiers;
}
void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
DeclContext *Ctx) {
NestedNameSpecifier NNS = std::nullopt;
unsigned NumSpecifiers = 0;
DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
// Eliminate common elements from the two DeclContext chains.
for (DeclContext *C : llvm::reverse(CurContextChain)) {
if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
break;
NamespaceDeclChain.pop_back();
}
// Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
// Add an explicit leading '::' specifier if needed.
if (NamespaceDeclChain.empty()) {
// Rebuild the NestedNameSpecifier as a globally-qualified specifier.
NNS = NestedNameSpecifier::getGlobal();
NumSpecifiers =
buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
} else if (NamedDecl *ND =
dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
IdentifierInfo *Name = ND->getIdentifier();
bool SameNameSpecifier = false;
if (llvm::is_contained(CurNameSpecifierIdentifiers, Name)) {
std::string NewNameSpecifier;
llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
NNS.print(SpecifierOStream, Context.getPrintingPolicy());
SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
}
if (SameNameSpecifier || llvm::is_contained(CurContextIdentifiers, Name)) {
// Rebuild the NestedNameSpecifier as a globally-qualified specifier.
NNS = NestedNameSpecifier::getGlobal();
NumSpecifiers =
buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
}
}
// If the built NestedNameSpecifier would be replacing an existing
// NestedNameSpecifier, use the number of component identifiers that
// would need to be changed as the edit distance instead of the number
// of components in the built NestedNameSpecifier.
if (NNS && !CurNameSpecifierIdentifiers.empty()) {
SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
NumSpecifiers =
llvm::ComputeEditDistance(llvm::ArrayRef(CurNameSpecifierIdentifiers),
llvm::ArrayRef(NewNameSpecifierIdentifiers));
}
SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
DistanceMap[NumSpecifiers].push_back(SI);
}
/// Perform name lookup for a possible result for typo correction.
static void LookupPotentialTypoResult(Sema &SemaRef,
LookupResult &Res,
IdentifierInfo *Name,
Scope *S, CXXScopeSpec *SS,
DeclContext *MemberContext,
bool EnteringContext,
bool isObjCIvarLookup,
bool FindHidden) {
Res.suppressDiagnostics();
Res.clear();
Res.setLookupName(Name);
Res.setAllowHidden(FindHidden);
if (MemberContext) {
if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
if (isObjCIvarLookup) {
if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
Res.addDecl(Ivar);
Res.resolveKind();
return;
}
}
if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
Res.addDecl(Prop);
Res.resolveKind();
return;
}
}
SemaRef.LookupQualifiedName(Res, MemberContext);
return;
}
SemaRef.LookupParsedName(Res, S, SS,
/*ObjectType=*/QualType(),
/*AllowBuiltinCreation=*/false, EnteringContext);
// Fake ivar lookup; this should really be part of
// LookupParsedName.
if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
if (Method->isInstanceMethod() && Method->getClassInterface() &&
(Res.empty() ||
(Res.isSingleResult() &&
Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
if (ObjCIvarDecl *IV
= Method->getClassInterface()->lookupInstanceVariable(Name)) {
Res.addDecl(IV);
Res.resolveKind();
}
}
}
}
/// Add keywords to the consumer as possible typo corrections.
static void AddKeywordsToConsumer(Sema &SemaRef,
TypoCorrectionConsumer &Consumer,
Scope *S, CorrectionCandidateCallback &CCC,
bool AfterNestedNameSpecifier) {
if (AfterNestedNameSpecifier) {
// For 'X::', we know exactly which keywords can appear next.
Consumer.addKeywordResult("template");
if (CCC.WantExpressionKeywords)
Consumer.addKeywordResult("operator");
return;
}
if (CCC.WantObjCSuper)
Consumer.addKeywordResult("super");
if (CCC.WantTypeSpecifiers) {
// Add type-specifier keywords to the set of results.
static const char *const CTypeSpecs[] = {
"char", "const", "double", "enum", "float", "int", "long", "short",
"signed", "struct", "union", "unsigned", "void", "volatile",
"_Complex",
// storage-specifiers as well
"extern", "inline", "static", "typedef"
};
for (const auto *CTS : CTypeSpecs)
Consumer.addKeywordResult(CTS);
if (SemaRef.getLangOpts().C99 && !SemaRef.getLangOpts().C2y)
Consumer.addKeywordResult("_Imaginary");
if (SemaRef.getLangOpts().C99)
Consumer.addKeywordResult("restrict");
if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
Consumer.addKeywordResult("bool");
else if (SemaRef.getLangOpts().C99)
Consumer.addKeywordResult("_Bool");
if (SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("class");
Consumer.addKeywordResult("typename");
Consumer.addKeywordResult("wchar_t");
if (SemaRef.getLangOpts().CPlusPlus11) {
Consumer.addKeywordResult("char16_t");
Consumer.addKeywordResult("char32_t");
Consumer.addKeywordResult("constexpr");
Consumer.addKeywordResult("decltype");
Consumer.addKeywordResult("thread_local");
}
}
if (SemaRef.getLangOpts().GNUKeywords)
Consumer.addKeywordResult("typeof");
} else if (CCC.WantFunctionLikeCasts) {
static const char *const CastableTypeSpecs[] = {
"char", "double", "float", "int", "long", "short",
"signed", "unsigned", "void"
};
for (auto *kw : CastableTypeSpecs)
Consumer.addKeywordResult(kw);
}
if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("const_cast");
Consumer.addKeywordResult("dynamic_cast");
Consumer.addKeywordResult("reinterpret_cast");
Consumer.addKeywordResult("static_cast");
}
if (CCC.WantExpressionKeywords) {
Consumer.addKeywordResult("sizeof");
if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("false");
Consumer.addKeywordResult("true");
}
if (SemaRef.getLangOpts().CPlusPlus) {
static const char *const CXXExprs[] = {
"delete", "new", "operator", "throw", "typeid"
};
for (const auto *CE : CXXExprs)
Consumer.addKeywordResult(CE);
if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
Consumer.addKeywordResult("this");
if (SemaRef.getLangOpts().CPlusPlus11) {
Consumer.addKeywordResult("alignof");
Consumer.addKeywordResult("nullptr");
}
}
if (SemaRef.getLangOpts().C11) {
// FIXME: We should not suggest _Alignof if the alignof macro
// is present.
Consumer.addKeywordResult("_Alignof");
}
}
if (CCC.WantRemainingKeywords) {
if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
// Statements.
static const char *const CStmts[] = {
"do", "else", "for", "goto", "if", "return", "switch", "while" };
for (const auto *CS : CStmts)
Consumer.addKeywordResult(CS);
if (SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("catch");
Consumer.addKeywordResult("try");
}
if (S && S->getBreakParent())
Consumer.addKeywordResult("break");
if (S && S->getContinueParent())
Consumer.addKeywordResult("continue");
if (SemaRef.getCurFunction() &&
!SemaRef.getCurFunction()->SwitchStack.empty()) {
Consumer.addKeywordResult("case");
Consumer.addKeywordResult("default");
}
} else {
if (SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("namespace");
Consumer.addKeywordResult("template");
}
if (S && S->isClassScope()) {
Consumer.addKeywordResult("explicit");
Consumer.addKeywordResult("friend");
Consumer.addKeywordResult("mutable");
Consumer.addKeywordResult("private");
Consumer.addKeywordResult("protected");
Consumer.addKeywordResult("public");
Consumer.addKeywordResult("virtual");
}
}
if (SemaRef.getLangOpts().CPlusPlus) {
Consumer.addKeywordResult("using");
if (SemaRef.getLangOpts().CPlusPlus11)
Consumer.addKeywordResult("static_assert");
}
}
}
std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC,
DeclContext *MemberContext, bool EnteringContext,
const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
DisableTypoCorrection)
return nullptr;
// In Microsoft mode, don't perform typo correction in a template member
// function dependent context because it interferes with the "lookup into
// dependent bases of class templates" feature.
if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
isa<CXXMethodDecl>(CurContext))
return nullptr;
// We only attempt to correct typos for identifiers.
IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
if (!Typo)
return nullptr;
// If the scope specifier itself was invalid, don't try to correct
// typos.
if (SS && SS->isInvalid())
return nullptr;
// Never try to correct typos during any kind of code synthesis.
if (!CodeSynthesisContexts.empty())
return nullptr;
// Don't try to correct 'super'.
if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
return nullptr;
// Abort if typo correction already failed for this specific typo.
IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
if (locs != TypoCorrectionFailures.end() &&
locs->second.count(TypoName.getLoc()))
return nullptr;
// Don't try to correct the identifier "vector" when in AltiVec mode.
// TODO: Figure out why typo correction misbehaves in this case, fix it, and
// remove this workaround.
if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
return nullptr;
// Provide a stop gap for files that are just seriously broken. Trying
// to correct all typos can turn into a HUGE performance penalty, causing
// some files to take minutes to get rejected by the parser.
unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
if (Limit && TyposCorrected >= Limit)
return nullptr;
++TyposCorrected;
// If we're handling a missing symbol error, using modules, and the
// special search all modules option is used, look for a missing import.
if (ErrorRecovery && getLangOpts().Modules &&
getLangOpts().ModulesSearchAll) {
// The following has the side effect of loading the missing module.
getModuleLoader().lookupMissingImports(Typo->getName(),
TypoName.getBeginLoc());
}
// Extend the lifetime of the callback. We delayed this until here
// to avoid allocations in the hot path (which is where no typo correction
// occurs). Note that CorrectionCandidateCallback is polymorphic and
// initially stack-allocated.
std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
auto Consumer = std::make_unique<TypoCorrectionConsumer>(
*this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext,
EnteringContext);
// Perform name lookup to find visible, similarly-named entities.
bool IsUnqualifiedLookup = false;
DeclContext *QualifiedDC = MemberContext;
if (MemberContext) {
LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
// Look in qualified interfaces.
if (OPT) {
for (auto *I : OPT->quals())
LookupVisibleDecls(I, LookupKind, *Consumer);
}
} else if (SS && SS->isSet()) {
QualifiedDC = computeDeclContext(*SS, EnteringContext);
if (!QualifiedDC)
return nullptr;
LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
} else {
IsUnqualifiedLookup = true;
}
// Determine whether we are going to search in the various namespaces for
// corrections.
bool SearchNamespaces
= getLangOpts().CPlusPlus &&
(IsUnqualifiedLookup || (SS && SS->isSet()));
if (IsUnqualifiedLookup || SearchNamespaces) {
// For unqualified lookup, look through all of the names that we have
// seen in this translation unit.
// FIXME: Re-add the ability to skip very unlikely potential corrections.
for (const auto &I : Context.Idents)
Consumer->FoundName(I.getKey());
// Walk through identifiers in external identifier sources.
// FIXME: Re-add the ability to skip very unlikely potential corrections.
if (IdentifierInfoLookup *External
= Context.Idents.getExternalIdentifierLookup()) {
std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
do {
StringRef Name = Iter->Next();
if (Name.empty())
break;
Consumer->FoundName(Name);
} while (true);
}
}
AddKeywordsToConsumer(*this, *Consumer, S,
*Consumer->getCorrectionValidator(),
SS && SS->isNotEmpty());
// Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
// to search those namespaces.
if (SearchNamespaces) {
// Load any externally-known namespaces.
if (ExternalSource && !LoadedExternalKnownNamespaces) {
SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
LoadedExternalKnownNamespaces = true;
ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
for (auto *N : ExternalKnownNamespaces)
KnownNamespaces[N] = true;
}
Consumer->addNamespaces(KnownNamespaces);
}
return Consumer;
}
TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
Sema::LookupNameKind LookupKind,
Scope *S, CXXScopeSpec *SS,
CorrectionCandidateCallback &CCC,
CorrectTypoKind Mode,
DeclContext *MemberContext,
bool EnteringContext,
const ObjCObjectPointerType *OPT,
bool RecordFailure) {
// Always let the ExternalSource have the first chance at correction, even
// if we would otherwise have given up.
if (ExternalSource) {
if (TypoCorrection Correction =
ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC,
MemberContext, EnteringContext, OPT))
return Correction;
}
// Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
// WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
// some instances of CTC_Unknown, while WantRemainingKeywords is true
// for CTC_Unknown but not for CTC_ObjCMessageReceiver.
bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
auto Consumer = makeTypoCorrectionConsumer(
TypoName, LookupKind, S, SS, CCC, MemberContext, EnteringContext, OPT,
Mode == CorrectTypoKind::ErrorRecovery);
if (!Consumer)
return TypoCorrection();
// If we haven't found anything, we're done.
if (Consumer->empty())
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
// Make sure the best edit distance (prior to adding any namespace qualifiers)
// is not more that about a third of the length of the typo's identifier.
unsigned ED = Consumer->getBestEditDistance(true);
unsigned TypoLen = Typo->getName().size();
if (ED > 0 && TypoLen / ED < 3)
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
TypoCorrection BestTC = Consumer->getNextCorrection();
TypoCorrection SecondBestTC = Consumer->getNextCorrection();
if (!BestTC)
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
ED = BestTC.getEditDistance();
if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
// If this was an unqualified lookup and we believe the callback
// object wouldn't have filtered out possible corrections, note
// that no correction was found.
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
}
// If only a single name remains, return that result.
if (!SecondBestTC ||
SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
const TypoCorrection &Result = BestTC;
// Don't correct to a keyword that's the same as the typo; the keyword
// wasn't actually in scope.
if (ED == 0 && Result.isKeyword())
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
TypoCorrection TC = Result;
TC.setCorrectionRange(SS, TypoName);
checkCorrectionVisibility(*this, TC);
return TC;
} else if (SecondBestTC && ObjCMessageReceiver) {
// Prefer 'super' when we're completing in a message-receiver
// context.
if (BestTC.getCorrection().getAsString() != "super") {
if (SecondBestTC.getCorrection().getAsString() == "super")
BestTC = SecondBestTC;
else if ((*Consumer)["super"].front().isKeyword())
BestTC = (*Consumer)["super"].front();
}
// Don't correct to a keyword that's the same as the typo; the keyword
// wasn't actually in scope.
if (BestTC.getEditDistance() == 0 ||
BestTC.getCorrection().getAsString() != "super")
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
BestTC.setCorrectionRange(SS, TypoName);
return BestTC;
}
// Record the failure's location if needed and return an empty correction. If
// this was an unqualified lookup and we believe the callback object did not
// filter out possible corrections, also cache the failure for the typo.
return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
}
void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
if (!CDecl) return;
if (isKeyword())
CorrectionDecls.clear();
CorrectionDecls.push_back(CDecl);
if (!CorrectionName)
CorrectionName = CDecl->getDeclName();
}
std::string TypoCorrection::getAsString(const LangOptions &LO) const {
if (CorrectionNameSpec) {
std::string tmpBuffer;
llvm::raw_string_ostream PrefixOStream(tmpBuffer);
CorrectionNameSpec.print(PrefixOStream, PrintingPolicy(LO));
PrefixOStream << CorrectionName;
return PrefixOStream.str();
}
return CorrectionName.getAsString();
}
bool CorrectionCandidateCallback::ValidateCandidate(
const TypoCorrection &candidate) {
if (!candidate.isResolved())
return true;
if (candidate.isKeyword())
return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
WantRemainingKeywords || WantObjCSuper;
bool HasNonType = false;
bool HasStaticMethod = false;
bool HasNonStaticMethod = false;
for (Decl *D : candidate) {
if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
D = FTD->getTemplatedDecl();
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
if (Method->isStatic())
HasStaticMethod = true;
else
HasNonStaticMethod = true;
}
if (!isa<TypeDecl>(D))
HasNonType = true;
}
if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
!candidate.getCorrectionSpecifier())
return false;
return WantTypeSpecifiers || HasNonType;
}
FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
bool HasExplicitTemplateArgs,
MemberExpr *ME)
: NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
CurContext(SemaRef.CurContext), MemberFn(ME) {
WantTypeSpecifiers = false;
WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
!HasExplicitTemplateArgs && NumArgs == 1;
WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
WantRemainingKeywords = false;
}
bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
if (!candidate.getCorrectionDecl())
return candidate.isKeyword();
for (auto *C : candidate) {
FunctionDecl *FD = nullptr;
NamedDecl *ND = C->getUnderlyingDecl();
if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
FD = FTD->getTemplatedDecl();
if (!HasExplicitTemplateArgs && !FD) {
if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
// If the Decl is neither a function nor a template function,
// determine if it is a pointer or reference to a function. If so,
// check against the number of arguments expected for the pointee.
QualType ValType = cast<ValueDecl>(ND)->getType();
if (ValType.isNull())
continue;
if (ValType->isAnyPointerType() || ValType->isReferenceType())
ValType = ValType->getPointeeType();
if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
if (FPT->getNumParams() == NumArgs)
return true;
}
}
// A typo for a function-style cast can look like a function call in C++.
if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr
: isa<TypeDecl>(ND)) &&
CurContext->getParentASTContext().getLangOpts().CPlusPlus)
// Only a class or class template can take two or more arguments.
return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND);
// Skip the current candidate if it is not a FunctionDecl or does not accept
// the current number of arguments.
if (!FD || !(FD->getNumParams() >= NumArgs &&
FD->getMinRequiredArguments() <= NumArgs))
continue;
// If the current candidate is a non-static C++ method, skip the candidate
// unless the method being corrected--or the current DeclContext, if the
// function being corrected is not a method--is a method in the same class
// or a descendent class of the candidate's parent class.
if (const auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
if (MemberFn || !MD->isStatic()) {
const auto *CurMD =
MemberFn
? dyn_cast_if_present<CXXMethodDecl>(MemberFn->getMemberDecl())
: dyn_cast_if_present<CXXMethodDecl>(CurContext);
const CXXRecordDecl *CurRD =
CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
const CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
continue;
}
}
return true;
}
return false;
}
void Sema::diagnoseTypo(const TypoCorrection &Correction,
const PartialDiagnostic &TypoDiag,
bool ErrorRecovery) {
diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
ErrorRecovery);
}
/// Find which declaration we should import to provide the definition of
/// the given declaration.
static const NamedDecl *getDefinitionToImport(const NamedDecl *D) {
if (const auto *VD = dyn_cast<VarDecl>(D))
return VD->getDefinition();
if (const auto *FD = dyn_cast<FunctionDecl>(D))
return FD->getDefinition();
if (const auto *TD = dyn_cast<TagDecl>(D))
return TD->getDefinition();
if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(D))
return ID->getDefinition();
if (const auto *PD = dyn_cast<ObjCProtocolDecl>(D))
return PD->getDefinition();
if (const auto *TD = dyn_cast<TemplateDecl>(D))
if (const NamedDecl *TTD = TD->getTemplatedDecl())
return getDefinitionToImport(TTD);
return nullptr;
}
void Sema::diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl,
MissingImportKind MIK, bool Recover) {
// Suggest importing a module providing the definition of this entity, if
// possible.
const NamedDecl *Def = getDefinitionToImport(Decl);
if (!Def)
Def = Decl;
Module *Owner = getOwningModule(Def);
assert(Owner && "definition of hidden declaration is not in a module");
llvm::SmallVector<Module*, 8> OwningModules;
OwningModules.push_back(Owner);
auto Merged = Context.getModulesWithMergedDefinition(Def);
llvm::append_range(OwningModules, Merged);
diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
Recover);
}
/// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
/// suggesting the addition of a #include of the specified file.
static std::string getHeaderNameForHeader(Preprocessor &PP, FileEntryRef E,
llvm::StringRef IncludingFile) {
bool IsAngled = false;
auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(
E, IncludingFile, &IsAngled);
return (IsAngled ? '<' : '"') + Path + (IsAngled ? '>' : '"');
}
void Sema::diagnoseMissingImport(SourceLocation UseLoc, const NamedDecl *Decl,
SourceLocation DeclLoc,
ArrayRef<Module *> Modules,
MissingImportKind MIK, bool Recover) {
assert(!Modules.empty());
// See https://github.com/llvm/llvm-project/issues/73893. It is generally
// confusing than helpful to show the namespace is not visible.
if (isa<NamespaceDecl>(Decl))
return;
auto NotePrevious = [&] {
// FIXME: Suppress the note backtrace even under
// -fdiagnostics-show-note-include-stack. We don't care how this
// declaration was previously reached.
Diag(DeclLoc, diag::note_unreachable_entity) << (int)MIK;
};
// Weed out duplicates from module list.
llvm::SmallVector<Module*, 8> UniqueModules;
llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
for (auto *M : Modules) {
if (M->isExplicitGlobalModule() || M->isPrivateModule())
continue;
if (UniqueModuleSet.insert(M).second)
UniqueModules.push_back(M);
}
// Try to find a suitable header-name to #include.
std::string HeaderName;
if (OptionalFileEntryRef Header =
PP.getHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) {
if (const FileEntry *FE =
SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc)))
HeaderName =
getHeaderNameForHeader(PP, *Header, FE->tryGetRealPathName());
}
// If we have a #include we should suggest, or if all definition locations
// were in global module fragments, don't suggest an import.
if (!HeaderName.empty() || UniqueModules.empty()) {
// FIXME: Find a smart place to suggest inserting a #include, and add
// a FixItHint there.
Diag(UseLoc, diag::err_module_unimported_use_header)
<< (int)MIK << Decl << !HeaderName.empty() << HeaderName;
// Produce a note showing where the entity was declared.
NotePrevious();
if (Recover)
createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
return;
}
Modules = UniqueModules;
auto GetModuleNameForDiagnostic = [this](const Module *M) -> std::string {
if (M->isModuleMapModule())
return M->getFullModuleName();
if (M->isImplicitGlobalModule())
M = M->getTopLevelModule();
// If the current module unit is in the same module with M, it is OK to show
// the partition name. Otherwise, it'll be sufficient to show the primary
// module name.
if (getASTContext().isInSameModule(M, getCurrentModule()))
return M->getTopLevelModuleName().str();
else
return M->getPrimaryModuleInterfaceName().str();
};
if (Modules.size() > 1) {
std::string ModuleList;
unsigned N = 0;
for (const auto *M : Modules) {
ModuleList += "\n ";
if (++N == 5 && N != Modules.size()) {
ModuleList += "[...]";
break;
}
ModuleList += GetModuleNameForDiagnostic(M);
}
Diag(UseLoc, diag::err_module_unimported_use_multiple)
<< (int)MIK << Decl << ModuleList;
} else {
// FIXME: Add a FixItHint that imports the corresponding module.
Diag(UseLoc, diag::err_module_unimported_use)
<< (int)MIK << Decl << GetModuleNameForDiagnostic(Modules[0]);
}
NotePrevious();
// Try to recover by implicitly importing this module.
if (Recover)
createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
}
void Sema::diagnoseTypo(const TypoCorrection &Correction,
const PartialDiagnostic &TypoDiag,
const PartialDiagnostic &PrevNote,
bool ErrorRecovery) {
std::string CorrectedStr = Correction.getAsString(getLangOpts());
std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
FixItHint FixTypo = FixItHint::CreateReplacement(
Correction.getCorrectionRange(), CorrectedStr);
// Maybe we're just missing a module import.
if (Correction.requiresImport()) {
NamedDecl *Decl = Correction.getFoundDecl();
assert(Decl && "import required but no declaration to import");
diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
MissingImportKind::Declaration, ErrorRecovery);
return;
}
Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
<< CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
NamedDecl *ChosenDecl =
Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
// For builtin functions which aren't declared anywhere in source,
// don't emit the "declared here" note.
if (const auto *FD = dyn_cast_if_present<FunctionDecl>(ChosenDecl);
FD && FD->getBuiltinID() &&
PrevNote.getDiagID() == diag::note_previous_decl &&
Correction.getCorrectionRange().getBegin() == FD->getBeginLoc()) {
ChosenDecl = nullptr;
}
if (PrevNote.getDiagID() && ChosenDecl)
Diag(ChosenDecl->getLocation(), PrevNote)
<< CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
// Add any extra diagnostics.
for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
Diag(Correction.getCorrectionRange().getBegin(), PD);
}
void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
DeclarationNameInfo Name(II, IILoc);
LookupResult R(*this, Name, LookupAnyName,
RedeclarationKind::NotForRedeclaration);
R.suppressDiagnostics();
R.setHideTags(false);
LookupName(R, S);
R.dump();
}
void Sema::ActOnPragmaDump(Expr *E) {
E->dump();
}
RedeclarationKind Sema::forRedeclarationInCurContext() const {
// A declaration with an owning module for linkage can never link against
// anything that is not visible. We don't need to check linkage here; if
// the context has internal linkage, redeclaration lookup won't find things
// from other TUs, and we can't safely compute linkage yet in general.
if (cast<Decl>(CurContext)->getOwningModuleForLinkage())
return RedeclarationKind::ForVisibleRedeclaration;
return RedeclarationKind::ForExternalRedeclaration;
}